Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git

Conflicts:
	drivers/mtd/mtd_blkdevs.c

Merge Grant's device-tree bits so that we can apply the subsequent fixes.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

25 files changed, 568 insertions, 378 deletions

diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c b/drivers/mtd/chips/cfi_cmdset_0002.c
index 288fc2ea849..3b8e32d8797 100644
--- a/drivers/mtd/chips/cfi_cmdset_0002.c
+++ b/drivers/mtd/chips/cfi_cmdset_0002.c
@@ -446,8 +446,8 @@ struct mtd_info *cfi_cmdset_0002(struct map_info *map, int primary)
 
 			/*
 			 * Valid primary extension versions are: 1.0, 1.1, 1.2, 1.3, 1.4
-			 * see: http://www.amd.com/us-en/assets/content_type/DownloadableAssets/cfi_r20.pdf, page 19
-			 *      http://www.amd.com/us-en/assets/content_type/DownloadableAssets/cfi_100_20011201.pdf
+			 * see: http://cs.ozerki.net/zap/pub/axim-x5/docs/cfi_r20.pdf, page 19 
+			 *      http://www.spansion.com/Support/AppNotes/cfi_100_20011201.pdf
 			 *      http://www.spansion.com/Support/Datasheets/s29ws-p_00_a12_e.pdf
 			 */
 			if (extp->MajorVersion != '1' ||
diff --git a/drivers/mtd/devices/lart.c b/drivers/mtd/devices/lart.c
index f4359fe7150..caf604167f0 100644
--- a/drivers/mtd/devices/lart.c
+++ b/drivers/mtd/devices/lart.c
@@ -17,7 +17,7 @@
  *           - January 2000
  *
  *    [2] MTD internal API documentation
- *           - http://www.linux-mtd.infradead.org/tech/
+ *           - http://www.linux-mtd.infradead.org/ 
  *
  * Limitations:
  *
diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index 7e0edd40ad4..669d2b7e36b 100644
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -928,6 +928,13 @@ static int __devinit m25p_probe(struct spi_device *spi)
 			nr_parts = data->nr_parts;
 		}
 
+#ifdef CONFIG_OF
+		if (nr_parts <= 0 && spi->dev.of_node) {
+			nr_parts = of_mtd_parse_partitions(&spi->dev,
+					spi->dev.of_node, &parts);
+		}
+#endif
+
 		if (nr_parts > 0) {
 			for (i = 0; i < nr_parts; i++) {
 				DEBUG(MTD_DEBUG_LEVEL2, "partitions[%d] = "
diff --git a/drivers/mtd/ftl.c b/drivers/mtd/ftl.c
index 4d6a64c387e..037b399df3f 100644
--- a/drivers/mtd/ftl.c
+++ b/drivers/mtd/ftl.c
@@ -51,7 +51,7 @@
 
     Use of the FTL format for non-PCMCIA applications may be an
     infringement of these patents.  For additional information,
-    contact M-Systems (http://www.m-sys.com) directly.
+    contact M-Systems directly. M-Systems since acquired by Sandisk. 
 
 ======================================================================*/
 #include <linux/mtd/blktrans.h>
diff --git a/drivers/mtd/maps/Kconfig b/drivers/mtd/maps/Kconfig
index e5eb65cfb3e..a0dd7bba948 100644
--- a/drivers/mtd/maps/Kconfig
+++ b/drivers/mtd/maps/Kconfig
@@ -172,7 +172,7 @@ config MTD_OCTAGON
 	  This provides a 'mapping' driver which supports the way in which
 	  the flash chips are connected in the Octagon-5066 Single Board
 	  Computer. More information on the board is available at
-	  <http://www.octagonsystems.com/CPUpages/5066.html>.
+	  <http://www.octagonsystems.com/products/5066.aspx>.
 
 config MTD_VMAX
 	tristate "JEDEC Flash device mapped on Tempustech VMAX SBC301"
@@ -293,7 +293,7 @@ config MTD_TQM8XXL
 	  chips, currently uses AMD one. This 'mapping' driver supports
 	  that arrangement, allowing the CFI probe and command set driver
 	  code to communicate with the chips on the TQM8xxL board. More at
-	  <http://www.denx.de/embedded-ppc-en.html>.
+	  <http://www.denx.de/wiki/PPCEmbedded/>.
 
 config MTD_RPXLITE
 	tristate "CFI Flash device mapped on RPX Lite or CLLF"
diff --git a/drivers/mtd/maps/pcmciamtd.c b/drivers/mtd/maps/pcmciamtd.c
index 86c74685eb7..91702294839 100644
--- a/drivers/mtd/maps/pcmciamtd.c
+++ b/drivers/mtd/maps/pcmciamtd.c
@@ -16,7 +16,6 @@
 #include <asm/io.h>
 #include <asm/system.h>
 
-#include <pcmcia/cs.h>
 #include <pcmcia/cistpl.h>
 #include <pcmcia/ds.h>
 
@@ -101,7 +100,7 @@ MODULE_PARM_DESC(mem_type, "Set Memory type (0=Flash, 1=RAM, 2=ROM, default=0)")
 static caddr_t remap_window(struct map_info *map, unsigned long to)
 {
 	struct pcmciamtd_dev *dev = (struct pcmciamtd_dev *)map->map_priv_1;
-	window_handle_t win = (window_handle_t)map->map_priv_2;
+	struct resource *win = (struct resource *) map->map_priv_2;
 	unsigned int offset;
 	int ret;
 
@@ -316,30 +315,19 @@ static void pcmciamtd_set_vpp(struct map_info *map, int on)
 {
 	struct pcmciamtd_dev *dev = (struct pcmciamtd_dev *)map->map_priv_1;
 	struct pcmcia_device *link = dev->p_dev;
-	modconf_t mod;
-	int ret;
-
-	mod.Attributes = CONF_VPP1_CHANGE_VALID | CONF_VPP2_CHANGE_VALID;
-	mod.Vcc = 0;
-	mod.Vpp1 = mod.Vpp2 = on ? dev->vpp : 0;
 
 	DEBUG(2, "dev = %p on = %d vpp = %d\n", dev, on, dev->vpp);
-	ret = pcmcia_modify_configuration(link, &mod);
+	pcmcia_fixup_vpp(link, on ? dev->vpp : 0);
 }
 
 
-/* After a card is removed, pcmciamtd_release() will unregister the
- * device, and release the PCMCIA configuration.  If the device is
- * still open, this will be postponed until it is closed.
- */
-
 static void pcmciamtd_release(struct pcmcia_device *link)
 {
 	struct pcmciamtd_dev *dev = link->priv;
 
 	DEBUG(3, "link = 0x%p", link);
 
-	if (link->win) {
+	if (link->resource[2]->end) {
 		if(dev->win_base) {
 			iounmap(dev->win_base);
 			dev->win_base = NULL;
@@ -482,18 +470,12 @@ static void card_settings(struct pcmciamtd_dev *dev, struct pcmcia_device *p_dev
 }
 
 
-/* pcmciamtd_config() is scheduled to run after a CARD_INSERTION event
- * is received, to configure the PCMCIA socket, and to make the
- * MTD device available to the system.
- */
-
 static int pcmciamtd_config(struct pcmcia_device *link)
 {
 	struct pcmciamtd_dev *dev = link->priv;
 	struct mtd_info *mtd = NULL;
-	win_req_t req;
 	int ret;
-	int i;
+	int i, j = 0;
 	static char *probes[] = { "jedec_probe", "cfi_probe" };
 	int new_name = 0;
 
@@ -520,28 +502,34 @@ static int pcmciamtd_config(struct pcmcia_device *link)
 	 * smaller windows until we succeed
 	 */
 
-	req.Attributes =  WIN_MEMORY_TYPE_CM | WIN_ENABLE;
-	req.Attributes |= (dev->pcmcia_map.bankwidth == 1) ? WIN_DATA_WIDTH_8 : WIN_DATA_WIDTH_16;
-	req.Base = 0;
-	req.AccessSpeed = mem_speed;
-	link->win = (window_handle_t)link;
-	req.Size = (force_size) ? force_size << 20 : MAX_PCMCIA_ADDR;
+	link->resource[2]->flags |=  WIN_MEMORY_TYPE_CM | WIN_ENABLE;
+	link->resource[2]->flags |= (dev->pcmcia_map.bankwidth == 1) ?
+					WIN_DATA_WIDTH_8 : WIN_DATA_WIDTH_16;
+	link->resource[2]->start = 0;
+	link->resource[2]->end = (force_size) ? force_size << 20 :
+					MAX_PCMCIA_ADDR;
 	dev->win_size = 0;
 
 	do {
 		int ret;
-		DEBUG(2, "requesting window with size = %dKiB memspeed = %d",
-		      req.Size >> 10, req.AccessSpeed);
-		ret = pcmcia_request_window(link, &req, &link->win);
+		DEBUG(2, "requesting window with size = %luKiB memspeed = %d",
+			(unsigned long) resource_size(link->resource[2]) >> 10,
+			mem_speed);
+		ret = pcmcia_request_window(link, link->resource[2], mem_speed);
 		DEBUG(2, "ret = %d dev->win_size = %d", ret, dev->win_size);
 		if(ret) {
-			req.Size >>= 1;
+			j++;
+			link->resource[2]->start = 0;
+			link->resource[2]->end = (force_size) ?
+					force_size << 20 : MAX_PCMCIA_ADDR;
+			link->resource[2]->end >>= j;
 		} else {
-			DEBUG(2, "Got window of size %dKiB", req.Size >> 10);
-			dev->win_size = req.Size;
+			DEBUG(2, "Got window of size %luKiB", (unsigned long)
+				resource_size(link->resource[2]) >> 10);
+			dev->win_size = resource_size(link->resource[2]);
 			break;
 		}
-	} while(req.Size >= 0x1000);
+	} while (link->resource[2]->end >= 0x1000);
 
 	DEBUG(2, "dev->win_size = %d", dev->win_size);
 
@@ -553,33 +541,31 @@ static int pcmciamtd_config(struct pcmcia_device *link)
 	DEBUG(1, "Allocated a window of %dKiB", dev->win_size >> 10);
 
 	/* Get write protect status */
-	DEBUG(2, "window handle = 0x%8.8lx", (unsigned long)link->win);
-	dev->win_base = ioremap(req.Base, req.Size);
+	dev->win_base = ioremap(link->resource[2]->start,
+				resource_size(link->resource[2]));
 	if(!dev->win_base) {
-		dev_err(&dev->p_dev->dev, "ioremap(%lu, %u) failed\n",
-			req.Base, req.Size);
+		dev_err(&dev->p_dev->dev, "ioremap(%pR) failed\n",
+			link->resource[2]);
 		pcmciamtd_release(link);
 		return -ENODEV;
 	}
-	DEBUG(1, "mapped window dev = %p req.base = 0x%lx base = %p size = 0x%x",
-	      dev, req.Base, dev->win_base, req.Size);
+	DEBUG(1, "mapped window dev = %p @ %pR, base = %p",
+	      dev, link->resource[2], dev->win_base);
 
 	dev->offset = 0;
 	dev->pcmcia_map.map_priv_1 = (unsigned long)dev;
-	dev->pcmcia_map.map_priv_2 = (unsigned long)link->win;
+	dev->pcmcia_map.map_priv_2 = (unsigned long)link->resource[2];
 
 	dev->vpp = (vpp) ? vpp : link->socket->socket.Vpp;
-	link->conf.Attributes = 0;
 	if(setvpp == 2) {
-		link->conf.Vpp = dev->vpp;
+		link->vpp = dev->vpp;
 	} else {
-		link->conf.Vpp = 0;
+		link->vpp = 0;
 	}
 
-	link->conf.IntType = INT_MEMORY;
-	link->conf.ConfigIndex = 0;
+	link->config_index = 0;
 	DEBUG(2, "Setting Configuration");
-	ret = pcmcia_request_configuration(link, &link->conf);
+	ret = pcmcia_enable_device(link);
 	if (ret != 0) {
 		if (dev->win_base) {
 			iounmap(dev->win_base);
@@ -676,12 +662,6 @@ static int pcmciamtd_resume(struct pcmcia_device *dev)
 }
 
 
-/* This deletes a driver "instance".  The device is de-registered
- * with Card Services.  If it has been released, all local data
- * structures are freed.  Otherwise, the structures will be freed
- * when the device is released.
- */
-
 static void pcmciamtd_detach(struct pcmcia_device *link)
 {
 	struct pcmciamtd_dev *dev = link->priv;
@@ -699,11 +679,6 @@ static void pcmciamtd_detach(struct pcmcia_device *link)
 }
 
 
-/* pcmciamtd_attach() creates an "instance" of the driver, allocating
- * local data structures for one device.  The device is registered
- * with Card Services.
- */
-
 static int pcmciamtd_probe(struct pcmcia_device *link)
 {
 	struct pcmciamtd_dev *dev;
@@ -716,9 +691,6 @@ static int pcmciamtd_probe(struct pcmcia_device *link)
 	dev->p_dev = link;
 	link->priv = dev;
 
-	link->conf.Attributes = 0;
-	link->conf.IntType = INT_MEMORY;
-
 	return pcmciamtd_config(link);
 }
 
@@ -753,9 +725,7 @@ static struct pcmcia_device_id pcmciamtd_ids[] = {
 MODULE_DEVICE_TABLE(pcmcia, pcmciamtd_ids);
 
 static struct pcmcia_driver pcmciamtd_driver = {
-	.drv		= {
-		.name	= "pcmciamtd"
-	},
+	.name		= "pcmciamtd",
 	.probe		= pcmciamtd_probe,
 	.remove		= pcmciamtd_detach,
 	.owner		= THIS_MODULE,
@@ -767,8 +737,6 @@ static struct pcmcia_driver pcmciamtd_driver = {
 
 static int __init init_pcmciamtd(void)
 {
-	info(DRIVER_DESC);
-
 	if(bankwidth && bankwidth != 1 && bankwidth != 2) {
 		info("bad bankwidth (%d), using default", bankwidth);
 		bankwidth = 2;
diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index 63790e975d2..f9329794f3b 100644
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -29,7 +29,6 @@
 #include <linux/blkdev.h>
 #include <linux/blkpg.h>
 #include <linux/spinlock.h>
-#include <linux/smp_lock.h>
 #include <linux/hdreg.h>
 #include <linux/init.h>
 #include <linux/mutex.h>
@@ -38,6 +37,7 @@
 
 #include "mtdcore.h"
 
+static DEFINE_MUTEX(mtd_blkdevs_mutex);
 static LIST_HEAD(blktrans_majors);
 static DEFINE_MUTEX(blktrans_ref_mutex);
 
@@ -185,6 +185,7 @@ static int blktrans_open(struct block_device *bdev, fmode_t mode)
 	if (!dev)
 		return -ERESTARTSYS; /* FIXME: busy loop! -arnd*/
 
+	mutex_lock(&mtd_blkdevs_mutex);
 	mutex_lock(&dev->lock);
 
 	if (dev->open++)
@@ -201,6 +202,7 @@ static int blktrans_open(struct block_device *bdev, fmode_t mode)
 unlock:
 	mutex_unlock(&dev->lock);
 	blktrans_dev_put(dev);
+	mutex_unlock(&mtd_blkdevs_mutex);
 	return ret;
 }
 
@@ -212,6 +214,7 @@ static int blktrans_release(struct gendisk *disk, fmode_t mode)
 	if (!dev)
 		return ret;
 
+	mutex_lock(&mtd_blkdevs_mutex);
 	mutex_lock(&dev->lock);
 
 	if (--dev->open)
@@ -227,6 +230,7 @@ static int blktrans_release(struct gendisk *disk, fmode_t mode)
 unlock:
 	mutex_unlock(&dev->lock);
 	blktrans_dev_put(dev);
+	mutex_unlock(&mtd_blkdevs_mutex);
 	return ret;
 }
 
@@ -259,6 +263,7 @@ static int blktrans_ioctl(struct block_device *bdev, fmode_t mode,
 	if (!dev)
 		return ret;
 
+	mutex_lock(&mtd_blkdevs_mutex);
 	mutex_lock(&dev->lock);
 
 	if (!dev->mtd)
@@ -273,6 +278,7 @@ static int blktrans_ioctl(struct block_device *bdev, fmode_t mode,
 	}
 unlock:
 	mutex_unlock(&dev->lock);
+	mutex_unlock(&mtd_blkdevs_mutex);
 	blktrans_dev_put(dev);
 	return ret;
 }
diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
index b7ed09c5790..3eff1e562ad 100644
--- a/drivers/mtd/mtdchar.c
+++ b/drivers/mtd/mtdchar.c
@@ -26,7 +26,7 @@
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/sched.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
 #include <linux/backing-dev.h>
 #include <linux/compat.h>
 #include <linux/mount.h>
@@ -38,6 +38,7 @@
 #include <asm/uaccess.h>
 
 #define MTD_INODE_FS_MAGIC 0x11307854
+static DEFINE_MUTEX(mtd_mutex);
 static struct vfsmount *mtd_inode_mnt __read_mostly;
 
 /*
@@ -91,7 +92,7 @@ static int mtd_open(struct inode *inode, struct file *file)
 	if ((file->f_mode & FMODE_WRITE) && (minor & 1))
 		return -EACCES;
 
-	lock_kernel();
+	mutex_lock(&mtd_mutex);
 	mtd = get_mtd_device(NULL, devnum);
 
 	if (IS_ERR(mtd)) {
@@ -139,7 +140,7 @@ static int mtd_open(struct inode *inode, struct file *file)
 	file->private_data = mfi;
 
 out:
-	unlock_kernel();
+	mutex_unlock(&mtd_mutex);
 	return ret;
 } /* mtd_open */
 
@@ -967,9 +968,9 @@ static long mtd_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
 {
 	int ret;
 
-	lock_kernel();
+	mutex_lock(&mtd_mutex);
 	ret = mtd_ioctl(file, cmd, arg);
-	unlock_kernel();
+	mutex_unlock(&mtd_mutex);
 
 	return ret;
 }
@@ -993,7 +994,7 @@ static long mtd_compat_ioctl(struct file *file, unsigned int cmd,
 	void __user *argp = compat_ptr(arg);
 	int ret = 0;
 
-	lock_kernel();
+	mutex_lock(&mtd_mutex);
 
 	switch (cmd) {
 	case MEMWRITEOOB32:
@@ -1028,7 +1029,7 @@ static long mtd_compat_ioctl(struct file *file, unsigned int cmd,
 		ret = mtd_ioctl(file, cmd, (unsigned long)argp);
 	}
 
-	unlock_kernel();
+	mutex_unlock(&mtd_mutex);
 
 	return ret;
 }
diff --git a/drivers/mtd/nand/cafe_nand.c b/drivers/mtd/nand/cafe_nand.c
index db1dfc5a1b1..e06c8983978 100644
--- a/drivers/mtd/nand/cafe_nand.c
+++ b/drivers/mtd/nand/cafe_nand.c
@@ -2,7 +2,7 @@
  * Driver for One Laptop Per Child ‘CAFÉ’ controller, aka Marvell 88ALP01
  *
  * The data sheet for this device can be found at:
- *    http://www.marvell.com/products/pcconn/88ALP01.jsp
+ *    http://wiki.laptop.org/go/Datasheets 
  *
  * Copyright © 2006 Red Hat, Inc.
  * Copyright © 2006 David Woodhouse <dwmw2@infradead.org>
diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
index b2828e84d24..214b03afdd4 100644
--- a/drivers/mtd/nand/mxc_nand.c
+++ b/drivers/mtd/nand/mxc_nand.c
@@ -30,6 +30,8 @@
 #include <linux/clk.h>
 #include <linux/err.h>
 #include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/completion.h>
 
 #include <asm/mach/flash.h>
 #include <mach/mxc_nand.h>
@@ -151,7 +153,7 @@ struct mxc_nand_host {
 	int			irq;
 	int			eccsize;
 
-	wait_queue_head_t	irq_waitq;
+	struct completion	op_completion;
 
 	uint8_t			*data_buf;
 	unsigned int		buf_start;
@@ -164,6 +166,7 @@ struct mxc_nand_host {
 	void			(*send_read_id)(struct mxc_nand_host *);
 	uint16_t		(*get_dev_status)(struct mxc_nand_host *);
 	int			(*check_int)(struct mxc_nand_host *);
+	void			(*irq_control)(struct mxc_nand_host *, int);
 };
 
 /* OOB placement block for use with hardware ecc generation */
@@ -216,9 +219,12 @@ static irqreturn_t mxc_nfc_irq(int irq, void *dev_id)
 {
 	struct mxc_nand_host *host = dev_id;
 
-	disable_irq_nosync(irq);
+	if (!host->check_int(host))
+		return IRQ_NONE;
 
-	wake_up(&host->irq_waitq);
+	host->irq_control(host, 0);
+
+	complete(&host->op_completion);
 
 	return IRQ_HANDLED;
 }
@@ -245,11 +251,54 @@ static int check_int_v1_v2(struct mxc_nand_host *host)
 	if (!(tmp & NFC_V1_V2_CONFIG2_INT))
 		return 0;
 
-	writew(tmp & ~NFC_V1_V2_CONFIG2_INT, NFC_V1_V2_CONFIG2);
+	if (!cpu_is_mx21())
+		writew(tmp & ~NFC_V1_V2_CONFIG2_INT, NFC_V1_V2_CONFIG2);
 
 	return 1;
 }
 
+/*
+ * It has been observed that the i.MX21 cannot read the CONFIG2:INT bit
+ * if interrupts are masked (CONFIG1:INT_MSK is set). To handle this, the
+ * driver can enable/disable the irq line rather than simply masking the
+ * interrupts.
+ */
+static void irq_control_mx21(struct mxc_nand_host *host, int activate)
+{
+	if (activate)
+		enable_irq(host->irq);
+	else
+		disable_irq_nosync(host->irq);
+}
+
+static void irq_control_v1_v2(struct mxc_nand_host *host, int activate)
+{
+	uint16_t tmp;
+
+	tmp = readw(NFC_V1_V2_CONFIG1);
+
+	if (activate)
+		tmp &= ~NFC_V1_V2_CONFIG1_INT_MSK;
+	else
+		tmp |= NFC_V1_V2_CONFIG1_INT_MSK;
+
+	writew(tmp, NFC_V1_V2_CONFIG1);
+}
+
+static void irq_control_v3(struct mxc_nand_host *host, int activate)
+{
+	uint32_t tmp;
+
+	tmp = readl(NFC_V3_CONFIG2);
+
+	if (activate)
+		tmp &= ~NFC_V3_CONFIG2_INT_MSK;
+	else
+		tmp |= NFC_V3_CONFIG2_INT_MSK;
+
+	writel(tmp, NFC_V3_CONFIG2);
+}
+
 /* This function polls the NANDFC to wait for the basic operation to
  * complete by checking the INT bit of config2 register.
  */
@@ -259,10 +308,9 @@ static void wait_op_done(struct mxc_nand_host *host, int useirq)
 
 	if (useirq) {
 		if (!host->check_int(host)) {
-
-			enable_irq(host->irq);
-
-			wait_event(host->irq_waitq, host->check_int(host));
+			INIT_COMPLETION(host->op_completion);
+			host->irq_control(host, 1);
+			wait_for_completion(&host->op_completion);
 		}
 	} else {
 		while (max_retries-- > 0) {
@@ -799,6 +847,7 @@ static void preset_v3(struct mtd_info *mtd)
 		NFC_V3_CONFIG2_2CMD_PHASES |
 		NFC_V3_CONFIG2_SPAS(mtd->oobsize >> 1) |
 		NFC_V3_CONFIG2_ST_CMD(0x70) |
+		NFC_V3_CONFIG2_INT_MSK |
 		NFC_V3_CONFIG2_NUM_ADDR_PHASE0;
 
 	if (chip->ecc.mode == NAND_ECC_HW)
@@ -1024,6 +1073,10 @@ static int __init mxcnd_probe(struct platform_device *pdev)
 		host->send_read_id = send_read_id_v1_v2;
 		host->get_dev_status = get_dev_status_v1_v2;
 		host->check_int = check_int_v1_v2;
+		if (cpu_is_mx21())
+			host->irq_control = irq_control_mx21;
+		else
+			host->irq_control = irq_control_v1_v2;
 	}
 
 	if (nfc_is_v21()) {
@@ -1062,6 +1115,7 @@ static int __init mxcnd_probe(struct platform_device *pdev)
 		host->send_read_id = send_read_id_v3;
 		host->check_int = check_int_v3;
 		host->get_dev_status = get_dev_status_v3;
+		host->irq_control = irq_control_v3;
 		oob_smallpage = &nandv2_hw_eccoob_smallpage;
 		oob_largepage = &nandv2_hw_eccoob_largepage;
 	} else
@@ -1093,14 +1147,34 @@ static int __init mxcnd_probe(struct platform_device *pdev)
 		this->options |= NAND_USE_FLASH_BBT;
 	}
 
-	init_waitqueue_head(&host->irq_waitq);
+	init_completion(&host->op_completion);
 
 	host->irq = platform_get_irq(pdev, 0);
 
+	/*
+	 * mask the interrupt. For i.MX21 explicitely call
+	 * irq_control_v1_v2 to use the mask bit. We can't call
+	 * disable_irq_nosync() for an interrupt we do not own yet.
+	 */
+	if (cpu_is_mx21())
+		irq_control_v1_v2(host, 0);
+	else
+		host->irq_control(host, 0);
+
 	err = request_irq(host->irq, mxc_nfc_irq, IRQF_DISABLED, DRIVER_NAME, host);
 	if (err)
 		goto eirq;
 
+	host->irq_control(host, 0);
+
+	/*
+	 * Now that the interrupt is disabled make sure the interrupt
+	 * mask bit is cleared on i.MX21. Otherwise we can't read
+	 * the interrupt status bit on this machine.
+	 */
+	if (cpu_is_mx21())
+		irq_control_v1_v2(host, 1);
+
 	/* first scan to find the device and get the page size */
 	if (nand_scan_ident(mtd, 1, NULL)) {
 		err = -ENXIO;
diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index 439e80d78ed..cd41c58b5bb 100644
--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -413,7 +413,7 @@ static inline int omap_nand_dma_transfer(struct mtd_info *mtd, void *addr,
 		prefetch_status = gpmc_read_status(GPMC_PREFETCH_COUNT);
 	} while (prefetch_status);
 	/* disable and stop the PFPW engine */
-	gpmc_prefetch_reset();
+	gpmc_prefetch_reset(info->gpmc_cs);
 
 	dma_unmap_single(&info->pdev->dev, dma_addr, len, dir);
 	return 0;
diff --git a/drivers/mtd/ubi/Kconfig b/drivers/mtd/ubi/Kconfig
index f702a163d8d..3cf193fb5e0 100644
--- a/drivers/mtd/ubi/Kconfig
+++ b/drivers/mtd/ubi/Kconfig
@@ -1,9 +1,5 @@
-menu "UBI - Unsorted block images"
-	depends on MTD
-
-config MTD_UBI
-	tristate "Enable UBI"
-	depends on MTD
+menuconfig MTD_UBI
+	tristate "Enable UBI - Unsorted block images"
 	select CRC32
 	help
 	  UBI is a software layer above MTD layer which admits of LVM-like
@@ -12,11 +8,12 @@ config MTD_UBI
 	  capabilities. Please, consult the MTD web site for more details
 	  (www.linux-mtd.infradead.org).
 
+if MTD_UBI
+
 config MTD_UBI_WL_THRESHOLD
 	int "UBI wear-leveling threshold"
 	default 4096
 	range 2 65536
-	depends on MTD_UBI
 	help
 	  This parameter defines the maximum difference between the highest
 	  erase counter value and the lowest erase counter value of eraseblocks
@@ -34,7 +31,6 @@ config MTD_UBI_BEB_RESERVE
 	int "Percentage of reserved eraseblocks for bad eraseblocks handling"
 	default 1
 	range 0 25
-	depends on MTD_UBI
 	help
 	  If the MTD device admits of bad eraseblocks (e.g. NAND flash), UBI
 	  reserves some amount of physical eraseblocks to handle new bad
@@ -48,8 +44,6 @@ config MTD_UBI_BEB_RESERVE
 
 config MTD_UBI_GLUEBI
 	tristate "MTD devices emulation driver (gluebi)"
-	default n
-	depends on MTD_UBI
 	help
 	   This option enables gluebi - an additional driver which emulates MTD
 	   devices on top of UBI volumes: for each UBI volumes an MTD device is
@@ -59,4 +53,5 @@ config MTD_UBI_GLUEBI
 	   software.
 
 source "drivers/mtd/ubi/Kconfig.debug"
-endmenu
+
+endif # MTD_UBI
diff --git a/drivers/mtd/ubi/Kconfig.debug b/drivers/mtd/ubi/Kconfig.debug
index 61f6e5e4045..fad4adc0fe2 100644
--- a/drivers/mtd/ubi/Kconfig.debug
+++ b/drivers/mtd/ubi/Kconfig.debug
@@ -1,94 +1,73 @@
 comment "UBI debugging options"
-	depends on MTD_UBI
 
 config MTD_UBI_DEBUG
 	bool "UBI debugging"
 	depends on SYSFS
-	depends on MTD_UBI
 	select DEBUG_FS
 	select KALLSYMS_ALL if KALLSYMS && DEBUG_KERNEL
 	help
 	  This option enables UBI debugging.
 
+if MTD_UBI_DEBUG
+
 config MTD_UBI_DEBUG_MSG
 	bool "UBI debugging messages"
-	depends on MTD_UBI_DEBUG
-	default n
 	help
 	  This option enables UBI debugging messages.
 
 config MTD_UBI_DEBUG_PARANOID
 	bool "Extra self-checks"
-	default n
-	depends on MTD_UBI_DEBUG
 	help
 	  This option enables extra checks in UBI code. Note this slows UBI down
 	  significantly.
 
 config MTD_UBI_DEBUG_DISABLE_BGT
 	bool "Do not enable the UBI background thread"
-	depends on MTD_UBI_DEBUG
-	default n
 	help
 	  This option switches the background thread off by default. The thread
 	  may be also be enabled/disabled via UBI sysfs.
 
 config MTD_UBI_DEBUG_EMULATE_BITFLIPS
 	bool "Emulate flash bit-flips"
-	depends on MTD_UBI_DEBUG
-	default n
 	help
 	  This option emulates bit-flips with probability 1/50, which in turn
 	  causes scrubbing. Useful for debugging and stressing UBI.
 
 config MTD_UBI_DEBUG_EMULATE_WRITE_FAILURES
 	bool "Emulate flash write failures"
-	depends on MTD_UBI_DEBUG
-	default n
 	help
 	  This option emulates write failures with probability 1/100. Useful for
 	  debugging and testing how UBI handlines errors.
 
 config MTD_UBI_DEBUG_EMULATE_ERASE_FAILURES
 	bool "Emulate flash erase failures"
-	depends on MTD_UBI_DEBUG
-	default n
 	help
 	  This option emulates erase failures with probability 1/100. Useful for
 	  debugging and testing how UBI handlines errors.
 
-menu "Additional UBI debugging messages"
-	depends on MTD_UBI_DEBUG
+comment "Additional UBI debugging messages"
 
 config MTD_UBI_DEBUG_MSG_BLD
 	bool "Additional UBI initialization and build messages"
-	default n
-	depends on MTD_UBI_DEBUG
 	help
 	  This option enables detailed UBI initialization and device build
 	  debugging messages.
 
 config MTD_UBI_DEBUG_MSG_EBA
 	bool "Eraseblock association unit messages"
-	default n
-	depends on MTD_UBI_DEBUG
 	help
 	  This option enables debugging messages from the UBI eraseblock
 	  association unit.
 
 config MTD_UBI_DEBUG_MSG_WL
 	bool "Wear-leveling unit messages"
-	default n
-	depends on MTD_UBI_DEBUG
 	help
 	  This option enables debugging messages from the UBI wear-leveling
 	  unit.
 
 config MTD_UBI_DEBUG_MSG_IO
 	bool "Input/output unit messages"
-	default n
-	depends on MTD_UBI_DEBUG
 	help
 	  This option enables debugging messages from the UBI input/output unit.
 
-endmenu # UBI debugging messages
+endif # MTD_UBI_DEBUG
diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index 78ae89488a4..5ebe280225d 100644
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -95,8 +95,8 @@ DEFINE_MUTEX(ubi_devices_mutex);
 static DEFINE_SPINLOCK(ubi_devices_lock);
 
 /* "Show" method for files in '/<sysfs>/class/ubi/' */
-static ssize_t ubi_version_show(struct class *class, struct class_attribute *attr,
-				char *buf)
+static ssize_t ubi_version_show(struct class *class,
+				struct class_attribute *attr, char *buf)
 {
 	return sprintf(buf, "%d\n", UBI_VERSION);
 }
@@ -591,6 +591,7 @@ static int attach_by_scanning(struct ubi_device *ubi)
 
 	ubi->bad_peb_count = si->bad_peb_count;
 	ubi->good_peb_count = ubi->peb_count - ubi->bad_peb_count;
+	ubi->corr_peb_count = si->corr_peb_count;
 	ubi->max_ec = si->max_ec;
 	ubi->mean_ec = si->mean_ec;
 	ubi_msg("max. sequence number:       %llu", si->max_sqnum);
@@ -972,6 +973,7 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
 	ubi_msg("MTD device size:            %llu MiB", ubi->flash_size >> 20);
 	ubi_msg("number of good PEBs:        %d", ubi->good_peb_count);
 	ubi_msg("number of bad PEBs:         %d", ubi->bad_peb_count);
+	ubi_msg("number of corrupted PEBs:   %d", ubi->corr_peb_count);
 	ubi_msg("max. allowed volumes:       %d", ubi->vtbl_slots);
 	ubi_msg("wear-leveling threshold:    %d", CONFIG_MTD_UBI_WL_THRESHOLD);
 	ubi_msg("number of internal volumes: %d", UBI_INT_VOL_COUNT);
diff --git a/drivers/mtd/ubi/cdev.c b/drivers/mtd/ubi/cdev.c
index 3d2d1a69e9a..af9fb0ff821 100644
--- a/drivers/mtd/ubi/cdev.c
+++ b/drivers/mtd/ubi/cdev.c
@@ -1100,4 +1100,5 @@ const struct file_operations ubi_ctrl_cdev_operations = {
 	.owner          = THIS_MODULE,
 	.unlocked_ioctl = ctrl_cdev_ioctl,
 	.compat_ioctl   = ctrl_cdev_compat_ioctl,
+	.llseek		= noop_llseek,
 };
diff --git a/drivers/mtd/ubi/debug.h b/drivers/mtd/ubi/debug.h
index 17a10712972..9eca95074bc 100644
--- a/drivers/mtd/ubi/debug.h
+++ b/drivers/mtd/ubi/debug.h
@@ -57,6 +57,9 @@ void ubi_dbg_dump_seb(const struct ubi_scan_leb *seb, int type);
 void ubi_dbg_dump_mkvol_req(const struct ubi_mkvol_req *req);
 void ubi_dbg_dump_flash(struct ubi_device *ubi, int pnum, int offset, int len);
 
+#define ubi_dbg_print_hex_dump(l, ps, pt, r, g, b, len, a)  \
+		print_hex_dump(l, ps, pt, r, g, b, len, a)
+
 #ifdef CONFIG_MTD_UBI_DEBUG_MSG
 /* General debugging messages */
 #define dbg_gen(fmt, ...) dbg_msg(fmt, ##__VA_ARGS__)
@@ -172,6 +175,7 @@ static inline int ubi_dbg_is_erase_failure(void)
 #define ubi_dbg_dump_seb(seb, type)      ({})
 #define ubi_dbg_dump_mkvol_req(req)      ({})
 #define ubi_dbg_dump_flash(ubi, pnum, offset, len) ({})
+#define ubi_dbg_print_hex_dump(l, ps, pt, r, g, b, len, a)  ({})
 
 #define UBI_IO_DEBUG               0
 #define DBG_DISABLE_BGT            0
diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c
index fe74749e0da..4be67181501 100644
--- a/drivers/mtd/ubi/eba.c
+++ b/drivers/mtd/ubi/eba.c
@@ -418,7 +418,7 @@ retry:
 				 * may try to recover data. FIXME: but this is
 				 * not implemented.
 				 */
-				if (err == UBI_IO_BAD_HDR_READ ||
+				if (err == UBI_IO_BAD_HDR_EBADMSG ||
 				    err == UBI_IO_BAD_HDR) {
 					ubi_warn("corrupted VID header at PEB "
 						 "%d, LEB %d:%d", pnum, vol_id,
@@ -963,7 +963,7 @@ write_error:
 static int is_error_sane(int err)
 {
 	if (err == -EIO || err == -ENOMEM || err == UBI_IO_BAD_HDR ||
-	    err == UBI_IO_BAD_HDR_READ || err == -ETIMEDOUT)
+	    err == UBI_IO_BAD_HDR_EBADMSG || err == -ETIMEDOUT)
 		return 0;
 	return 1;
 }
@@ -1201,6 +1201,9 @@ static void print_rsvd_warning(struct ubi_device *ubi,
 
 	ubi_warn("cannot reserve enough PEBs for bad PEB handling, reserved %d,"
 		 " need %d", ubi->beb_rsvd_pebs, ubi->beb_rsvd_level);
+	if (ubi->corr_peb_count)
+		ubi_warn("%d PEBs are corrupted and not used",
+			ubi->corr_peb_count);
 }
 
 /**
@@ -1263,6 +1266,9 @@ int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si)
 	if (ubi->avail_pebs < EBA_RESERVED_PEBS) {
 		ubi_err("no enough physical eraseblocks (%d, need %d)",
 			ubi->avail_pebs, EBA_RESERVED_PEBS);
+		if (ubi->corr_peb_count)
+			ubi_err("%d PEBs are corrupted and not used",
+				ubi->corr_peb_count);
 		err = -ENOSPC;
 		goto out_free;
 	}
diff --git a/drivers/mtd/ubi/io.c b/drivers/mtd/ubi/io.c
index 332f992f13d..c2960ac9f39 100644
--- a/drivers/mtd/ubi/io.c
+++ b/drivers/mtd/ubi/io.c
@@ -376,25 +376,6 @@ retry:
 	return 0;
 }
 
-/**
- * check_pattern - check if buffer contains only a certain byte pattern.
- * @buf: buffer to check
- * @patt: the pattern to check
- * @size: buffer size in bytes
- *
- * This function returns %1 in there are only @patt bytes in @buf, and %0 if
- * something else was also found.
- */
-static int check_pattern(const void *buf, uint8_t patt, int size)
-{
-	int i;
-
-	for (i = 0; i < size; i++)
-		if (((const uint8_t *)buf)[i] != patt)
-			return 0;
-	return 1;
-}
-
 /* Patterns to write to a physical eraseblock when torturing it */
 static uint8_t patterns[] = {0xa5, 0x5a, 0x0};
 
@@ -426,7 +407,7 @@ static int torture_peb(struct ubi_device *ubi, int pnum)
 		if (err)
 			goto out;
 
-		err = check_pattern(ubi->peb_buf1, 0xFF, ubi->peb_size);
+		err = ubi_check_pattern(ubi->peb_buf1, 0xFF, ubi->peb_size);
 		if (err == 0) {
 			ubi_err("erased PEB %d, but a non-0xFF byte found",
 				pnum);
@@ -445,7 +426,8 @@ static int torture_peb(struct ubi_device *ubi, int pnum)
 		if (err)
 			goto out;
 
-		err = check_pattern(ubi->peb_buf1, patterns[i], ubi->peb_size);
+		err = ubi_check_pattern(ubi->peb_buf1, patterns[i],
+					ubi->peb_size);
 		if (err == 0) {
 			ubi_err("pattern %x checking failed for PEB %d",
 				patterns[i], pnum);
@@ -517,7 +499,7 @@ static int nor_erase_prepare(struct ubi_device *ubi, int pnum)
 	 * In this case we probably anyway have garbage in this PEB.
 	 */
 	err1 = ubi_io_read_vid_hdr(ubi, pnum, &vid_hdr, 0);
-	if (err1 == UBI_IO_BAD_HDR_READ || err1 == UBI_IO_BAD_HDR)
+	if (err1 == UBI_IO_BAD_HDR_EBADMSG || err1 == UBI_IO_BAD_HDR)
 		/*
 		 * The VID header is corrupted, so we can safely erase this
 		 * PEB and not afraid that it will be treated as a valid PEB in
@@ -712,47 +694,47 @@ bad:
  *   and corrected by the flash driver; this is harmless but may indicate that
  *   this eraseblock may become bad soon (but may be not);
  * o %UBI_IO_BAD_HDR if the erase counter header is corrupted (a CRC error);
- * o %UBI_IO_PEB_EMPTY if the physical eraseblock is empty;
+ * o %UBI_IO_BAD_HDR_EBADMSG is the same as %UBI_IO_BAD_HDR, but there also was
+ *   a data integrity error (uncorrectable ECC error in case of NAND);
+ * o %UBI_IO_FF if only 0xFF bytes were read (the PEB is supposedly empty)
  * o a negative error code in case of failure.
  */
 int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
 		       struct ubi_ec_hdr *ec_hdr, int verbose)
 {
-	int err, read_err = 0;
+	int err, read_err;
 	uint32_t crc, magic, hdr_crc;
 
 	dbg_io("read EC header from PEB %d", pnum);
 	ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
 
-	err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE);
-	if (err) {
-		if (err != UBI_IO_BITFLIPS && err != -EBADMSG)
-			return err;
+	read_err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE);
+	if (read_err) {
+		if (read_err != UBI_IO_BITFLIPS && read_err != -EBADMSG)
+			return read_err;
 
 		/*
 		 * We read all the data, but either a correctable bit-flip
-		 * occurred, or MTD reported about some data integrity error,
-		 * like an ECC error in case of NAND. The former is harmless,
-		 * the later may mean that the read data is corrupted. But we
-		 * have a CRC check-sum and we will detect this. If the EC
-		 * header is still OK, we just report this as there was a
-		 * bit-flip.
+		 * occurred, or MTD reported a data integrity error
+		 * (uncorrectable ECC error in case of NAND). The former is
+		 * harmless, the later may mean that the read data is
+		 * corrupted. But we have a CRC check-sum and we will detect
+		 * this. If the EC header is still OK, we just report this as
+		 * there was a bit-flip, to force scrubbing.
 		 */
-		if (err == -EBADMSG)
-			read_err = UBI_IO_BAD_HDR_READ;
 	}
 
 	magic = be32_to_cpu(ec_hdr->magic);
 	if (magic != UBI_EC_HDR_MAGIC) {
-		if (read_err)
-			return read_err;
+		if (read_err == -EBADMSG)
+			return UBI_IO_BAD_HDR_EBADMSG;
 
 		/*
 		 * The magic field is wrong. Let's check if we have read all
 		 * 0xFF. If yes, this physical eraseblock is assumed to be
 		 * empty.
 		 */
-		if (check_pattern(ec_hdr, 0xFF, UBI_EC_HDR_SIZE)) {
+		if (ubi_check_pattern(ec_hdr, 0xFF, UBI_EC_HDR_SIZE)) {
 			/* The physical eraseblock is supposedly empty */
 			if (verbose)
 				ubi_warn("no EC header found at PEB %d, "
@@ -760,7 +742,10 @@ int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
 			else if (UBI_IO_DEBUG)
 				dbg_msg("no EC header found at PEB %d, "
 					"only 0xFF bytes", pnum);
-			return UBI_IO_PEB_EMPTY;
+			if (!read_err)
+				return UBI_IO_FF;
+			else
+				return UBI_IO_FF_BITFLIPS;
 		}
 
 		/*
@@ -788,7 +773,11 @@ int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
 		} else if (UBI_IO_DEBUG)
 			dbg_msg("bad EC header CRC at PEB %d, calculated "
 				"%#08x, read %#08x", pnum, crc, hdr_crc);
-		return read_err ?: UBI_IO_BAD_HDR;
+
+		if (!read_err)
+			return UBI_IO_BAD_HDR;
+		else
+			return UBI_IO_BAD_HDR_EBADMSG;
 	}
 
 	/* And of course validate what has just been read from the media */
@@ -975,22 +964,16 @@ bad:
  *
  * This function reads the volume identifier header from physical eraseblock
  * @pnum and stores it in @vid_hdr. It also checks CRC checksum of the read
- * volume identifier header. The following codes may be returned:
+ * volume identifier header. The error codes are the same as in
+ * 'ubi_io_read_ec_hdr()'.
  *
- * o %0 if the CRC checksum is correct and the header was successfully read;
- * o %UBI_IO_BITFLIPS if the CRC is correct, but bit-flips were detected
- *   and corrected by the flash driver; this is harmless but may indicate that
- *   this eraseblock may become bad soon;
- * o %UBI_IO_BAD_HDR if the volume identifier header is corrupted (a CRC
- *   error detected);
- * o %UBI_IO_PEB_FREE if the physical eraseblock is free (i.e., there is no VID
- *   header there);
- * o a negative error code in case of failure.
+ * Note, the implementation of this function is also very similar to
+ * 'ubi_io_read_ec_hdr()', so refer commentaries in 'ubi_io_read_ec_hdr()'.
  */
 int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
 			struct ubi_vid_hdr *vid_hdr, int verbose)
 {
-	int err, read_err = 0;
+	int err, read_err;
 	uint32_t crc, magic, hdr_crc;
 	void *p;
 
@@ -998,48 +981,29 @@ int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
 	ubi_assert(pnum >= 0 &&  pnum < ubi->peb_count);
 
 	p = (char *)vid_hdr - ubi->vid_hdr_shift;
-	err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset,
+	read_err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset,
 			  ubi->vid_hdr_alsize);
-	if (err) {
-		if (err != UBI_IO_BITFLIPS && err != -EBADMSG)
-			return err;
-
-		/*
-		 * We read all the data, but either a correctable bit-flip
-		 * occurred, or MTD reported about some data integrity error,
-		 * like an ECC error in case of NAND. The former is harmless,
-		 * the later may mean the read data is corrupted. But we have a
-		 * CRC check-sum and we will identify this. If the VID header is
-		 * still OK, we just report this as there was a bit-flip.
-		 */
-		if (err == -EBADMSG)
-			read_err = UBI_IO_BAD_HDR_READ;
-	}
+	if (read_err && read_err != UBI_IO_BITFLIPS && read_err != -EBADMSG)
+		return read_err;
 
 	magic = be32_to_cpu(vid_hdr->magic);
 	if (magic != UBI_VID_HDR_MAGIC) {
-		if (read_err)
-			return read_err;
+		if (read_err == -EBADMSG)
+			return UBI_IO_BAD_HDR_EBADMSG;
 
-		/*
-		 * If we have read all 0xFF bytes, the VID header probably does
-		 * not exist and the physical eraseblock is assumed to be free.
-		 */
-		if (check_pattern(vid_hdr, 0xFF, UBI_VID_HDR_SIZE)) {
-			/* The physical eraseblock is supposedly free */
+		if (ubi_check_pattern(vid_hdr, 0xFF, UBI_VID_HDR_SIZE)) {
 			if (verbose)
 				ubi_warn("no VID header found at PEB %d, "
 					 "only 0xFF bytes", pnum);
 			else if (UBI_IO_DEBUG)
 				dbg_msg("no VID header found at PEB %d, "
 					"only 0xFF bytes", pnum);
-			return UBI_IO_PEB_FREE;
+			if (!read_err)
+				return UBI_IO_FF;
+			else
+				return UBI_IO_FF_BITFLIPS;
 		}
 
-		/*
-		 * This is not a valid VID header, and these are not 0xFF
-		 * bytes. Report that the header is corrupted.
-		 */
 		if (verbose) {
 			ubi_warn("bad magic number at PEB %d: %08x instead of "
 				 "%08x", pnum, magic, UBI_VID_HDR_MAGIC);
@@ -1061,20 +1025,18 @@ int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
 		} else if (UBI_IO_DEBUG)
 			dbg_msg("bad CRC at PEB %d, calculated %#08x, "
 				"read %#08x", pnum, crc, hdr_crc);
-		return read_err ?: UBI_IO_BAD_HDR;
+		if (!read_err)
+			return UBI_IO_BAD_HDR;
+		else
+			return UBI_IO_BAD_HDR_EBADMSG;
 	}
 
-	/* Validate the VID header that we have just read */
 	err = validate_vid_hdr(ubi, vid_hdr);
 	if (err) {
 		ubi_err("validation failed for PEB %d", pnum);
 		return -EINVAL;
 	}
 
-	/*
-	 * If there was a read error (%-EBADMSG), but the header CRC is still
-	 * OK, report about a bit-flip to force scrubbing on this PEB.
-	 */
 	return read_err ? UBI_IO_BITFLIPS : 0;
 }
 
@@ -1383,7 +1345,7 @@ int ubi_dbg_check_all_ff(struct ubi_device *ubi, int pnum, int offset, int len)
 		goto error;
 	}
 
-	err = check_pattern(ubi->dbg_peb_buf, 0xFF, len);
+	err = ubi_check_pattern(ubi->dbg_peb_buf, 0xFF, len);
 	if (err == 0) {
 		ubi_err("flash region at PEB %d:%d, length %d does not "
 			"contain all 0xFF bytes", pnum, offset, len);
diff --git a/drivers/mtd/ubi/misc.c b/drivers/mtd/ubi/misc.c
index 22ad3140294..ff2a65c37f6 100644
--- a/drivers/mtd/ubi/misc.c
+++ b/drivers/mtd/ubi/misc.c
@@ -103,3 +103,22 @@ void ubi_calculate_reserved(struct ubi_device *ubi)
 	if (ubi->beb_rsvd_level < MIN_RESEVED_PEBS)
 		ubi->beb_rsvd_level = MIN_RESEVED_PEBS;
 }
+
+/**
+ * ubi_check_pattern - check if buffer contains only a certain byte pattern.
+ * @buf: buffer to check
+ * @patt: the pattern to check
+ * @size: buffer size in bytes
+ *
+ * This function returns %1 in there are only @patt bytes in @buf, and %0 if
+ * something else was also found.
+ */
+int ubi_check_pattern(const void *buf, uint8_t patt, int size)
+{
+	int i;
+
+	for (i = 0; i < size; i++)
+		if (((const uint8_t *)buf)[i] != patt)
+			return 0;
+	return 1;
+}
diff --git a/drivers/mtd/ubi/scan.c b/drivers/mtd/ubi/scan.c
index 69b52e9c948..3c631863bf4 100644
--- a/drivers/mtd/ubi/scan.c
+++ b/drivers/mtd/ubi/scan.c
@@ -29,7 +29,7 @@
  * objects which are kept in volume RB-tree with root at the @volumes field.
  * The RB-tree is indexed by the volume ID.
  *
- * Found logical eraseblocks are represented by &struct ubi_scan_leb objects.
+ * Scanned logical eraseblocks are represented by &struct ubi_scan_leb objects.
  * These objects are kept in per-volume RB-trees with the root at the
  * corresponding &struct ubi_scan_volume object. To put it differently, we keep
  * an RB-tree of per-volume objects and each of these objects is the root of
@@ -38,6 +38,33 @@
  * Corrupted physical eraseblocks are put to the @corr list, free physical
  * eraseblocks are put to the @free list and the physical eraseblock to be
  * erased are put to the @erase list.
+ *
+ * UBI tries to distinguish between 2 types of corruptions.
+ * 1. Corruptions caused by power cuts. These are harmless and expected
+ *    corruptions and UBI tries to handle them gracefully, without printing too
+ *    many warnings and error messages. The idea is that we do not lose
+ *    important data in these case - we may lose only the data which was being
+ *    written to the media just before the power cut happened, and the upper
+ *    layers (e.g., UBIFS) are supposed to handle these situations. UBI puts
+ *    these PEBs to the head of the @erase list and they are scheduled for
+ *    erasure.
+ *
+ * 2. Unexpected corruptions which are not caused by power cuts. During
+ *    scanning, such PEBs are put to the @corr list and UBI preserves them.
+ *    Obviously, this lessens the amount of available PEBs, and if at some
+ *    point UBI runs out of free PEBs, it switches to R/O mode. UBI also loudly
+ *    informs about such PEBs every time the MTD device is attached.
+ *
+ * However, it is difficult to reliably distinguish between these types of
+ * corruptions and UBI's strategy is as follows. UBI assumes (2.) if the VID
+ * header is corrupted and the data area does not contain all 0xFFs, and there
+ * were not bit-flips or integrity errors while reading the data area. Otherwise
+ * UBI assumes (1.). The assumptions are:
+ *   o if the data area contains only 0xFFs, there is no data, and it is safe
+ *     to just erase this PEB.
+ *   o if the data area has bit-flips and data integrity errors (ECC errors on
+ *     NAND), it is probably a PEB which was being erased when power cut
+ *     happened.
  */
 
 #include <linux/err.h>
@@ -62,26 +89,26 @@ static struct ubi_vid_hdr *vidh;
  * @si: scanning information
  * @pnum: physical eraseblock number to add
  * @ec: erase counter of the physical eraseblock
+ * @to_head: if not zero, add to the head of the list
  * @list: the list to add to
  *
- * This function adds physical eraseblock @pnum to free, erase, corrupted or
- * alien lists. Returns zero in case of success and a negative error code in
- * case of failure.
+ * This function adds physical eraseblock @pnum to free, erase, or alien lists.
+ * If @to_head is not zero, PEB will be added to the head of the list, which
+ * basically means it will be processed first later. E.g., we add corrupted
+ * PEBs (corrupted due to power cuts) to the head of the erase list to make
+ * sure we erase them first and get rid of corruptions ASAP. This function
+ * returns zero in case of success and a negative error code in case of
+ * failure.
  */
-static int add_to_list(struct ubi_scan_info *si, int pnum, int ec,
+static int add_to_list(struct ubi_scan_info *si, int pnum, int ec, int to_head,
 		       struct list_head *list)
 {
 	struct ubi_scan_leb *seb;
 
 	if (list == &si->free) {
 		dbg_bld("add to free: PEB %d, EC %d", pnum, ec);
-		si->free_peb_count += 1;
 	} else if (list == &si->erase) {
 		dbg_bld("add to erase: PEB %d, EC %d", pnum, ec);
-		si->erase_peb_count += 1;
-	} else if (list == &si->corr) {
-		dbg_bld("add to corrupted: PEB %d, EC %d", pnum, ec);
-		si->corr_peb_count += 1;
 	} else if (list == &si->alien) {
 		dbg_bld("add to alien: PEB %d, EC %d", pnum, ec);
 		si->alien_peb_count += 1;
@@ -94,7 +121,37 @@ static int add_to_list(struct ubi_scan_info *si, int pnum, int ec,
 
 	seb->pnum = pnum;
 	seb->ec = ec;
-	list_add_tail(&seb->u.list, list);
+	if (to_head)
+		list_add(&seb->u.list, list);
+	else
+		list_add_tail(&seb->u.list, list);
+	return 0;
+}
+
+/**
+ * add_corrupted - add a corrupted physical eraseblock.
+ * @si: scanning information
+ * @pnum: physical eraseblock number to add
+ * @ec: erase counter of the physical eraseblock
+ *
+ * This function adds corrupted physical eraseblock @pnum to the 'corr' list.
+ * The corruption was presumably not caused by a power cut. Returns zero in
+ * case of success and a negative error code in case of failure.
+ */
+static int add_corrupted(struct ubi_scan_info *si, int pnum, int ec)
+{
+	struct ubi_scan_leb *seb;
+
+	dbg_bld("add to corrupted: PEB %d, EC %d", pnum, ec);
+
+	seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL);
+	if (!seb)
+		return -ENOMEM;
+
+	si->corr_peb_count += 1;
+	seb->pnum = pnum;
+	seb->ec = ec;
+	list_add(&seb->u.list, &si->corr);
 	return 0;
 }
 
@@ -258,8 +315,8 @@ static int compare_lebs(struct ubi_device *ubi, const struct ubi_scan_leb *seb,
 		 * created before sequence numbers support has been added. At
 		 * that times we used 32-bit LEB versions stored in logical
 		 * eraseblocks. That was before UBI got into mainline. We do not
-		 * support these images anymore. Well, those images will work
-		 * still work, but only if no unclean reboots happened.
+		 * support these images anymore. Well, those images still work,
+		 * but only if no unclean reboots happened.
 		 */
 		ubi_err("unsupported on-flash UBI format\n");
 		return -EINVAL;
@@ -285,19 +342,25 @@ static int compare_lebs(struct ubi_device *ubi, const struct ubi_scan_leb *seb,
 			return 1;
 		}
 	} else {
-		pnum = seb->pnum;
+		if (!seb->copy_flag) {
+			/* It is not a copy, so it is newer */
+			dbg_bld("first PEB %d is newer, copy_flag is unset",
+				pnum);
+			return bitflips << 1;
+		}
 
 		vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
 		if (!vh)
 			return -ENOMEM;
 
+		pnum = seb->pnum;
 		err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
 		if (err) {
 			if (err == UBI_IO_BITFLIPS)
 				bitflips = 1;
 			else {
 				dbg_err("VID of PEB %d header is bad, but it "
-					"was OK earlier", pnum);
+					"was OK earlier, err %d", pnum, err);
 				if (err > 0)
 					err = -EIO;
 
@@ -305,14 +368,6 @@ static int compare_lebs(struct ubi_device *ubi, const struct ubi_scan_leb *seb,
 			}
 		}
 
-		if (!vh->copy_flag) {
-			/* It is not a copy, so it is newer */
-			dbg_bld("first PEB %d is newer, copy_flag is unset",
-				pnum);
-			err = bitflips << 1;
-			goto out_free_vidh;
-		}
-
 		vid_hdr = vh;
 	}
 
@@ -463,18 +518,15 @@ int ubi_scan_add_used(struct ubi_device *ubi, struct ubi_scan_info *si,
 			if (err)
 				return err;
 
-			if (cmp_res & 4)
-				err = add_to_list(si, seb->pnum, seb->ec,
-						  &si->corr);
-			else
-				err = add_to_list(si, seb->pnum, seb->ec,
-						  &si->erase);
+			err = add_to_list(si, seb->pnum, seb->ec, cmp_res & 4,
+					  &si->erase);
 			if (err)
 				return err;
 
 			seb->ec = ec;
 			seb->pnum = pnum;
 			seb->scrub = ((cmp_res & 2) || bitflips);
+			seb->copy_flag = vid_hdr->copy_flag;
 			seb->sqnum = sqnum;
 
 			if (sv->highest_lnum == lnum)
@@ -487,10 +539,8 @@ int ubi_scan_add_used(struct ubi_device *ubi, struct ubi_scan_info *si,
 			 * This logical eraseblock is older than the one found
 			 * previously.
 			 */
-			if (cmp_res & 4)
-				return add_to_list(si, pnum, ec, &si->corr);
-			else
-				return add_to_list(si, pnum, ec, &si->erase);
+			return add_to_list(si, pnum, ec, cmp_res & 4,
+					   &si->erase);
 		}
 	}
 
@@ -510,8 +560,9 @@ int ubi_scan_add_used(struct ubi_device *ubi, struct ubi_scan_info *si,
 	seb->ec = ec;
 	seb->pnum = pnum;
 	seb->lnum = lnum;
-	seb->sqnum = sqnum;
 	seb->scrub = bitflips;
+	seb->copy_flag = vid_hdr->copy_flag;
+	seb->sqnum = sqnum;
 
 	if (sv->highest_lnum <= lnum) {
 		sv->highest_lnum = lnum;
@@ -521,7 +572,6 @@ int ubi_scan_add_used(struct ubi_device *ubi, struct ubi_scan_info *si,
 	sv->leb_count += 1;
 	rb_link_node(&seb->u.rb, parent, p);
 	rb_insert_color(&seb->u.rb, &sv->root);
-	si->used_peb_count += 1;
 	return 0;
 }
 
@@ -668,8 +718,8 @@ out_free:
 struct ubi_scan_leb *ubi_scan_get_free_peb(struct ubi_device *ubi,
 					   struct ubi_scan_info *si)
 {
-	int err = 0, i;
-	struct ubi_scan_leb *seb;
+	int err = 0;
+	struct ubi_scan_leb *seb, *tmp_seb;
 
 	if (!list_empty(&si->free)) {
 		seb = list_entry(si->free.next, struct ubi_scan_leb, u.list);
@@ -678,38 +728,86 @@ struct ubi_scan_leb *ubi_scan_get_free_peb(struct ubi_device *ubi,
 		return seb;
 	}
 
-	for (i = 0; i < 2; i++) {
-		struct list_head *head;
-		struct ubi_scan_leb *tmp_seb;
+	/*
+	 * We try to erase the first physical eraseblock from the erase list
+	 * and pick it if we succeed, or try to erase the next one if not. And
+	 * so forth. We don't want to take care about bad eraseblocks here -
+	 * they'll be handled later.
+	 */
+	list_for_each_entry_safe(seb, tmp_seb, &si->erase, u.list) {
+		if (seb->ec == UBI_SCAN_UNKNOWN_EC)
+			seb->ec = si->mean_ec;
 
-		if (i == 0)
-			head = &si->erase;
-		else
-			head = &si->corr;
+		err = ubi_scan_erase_peb(ubi, si, seb->pnum, seb->ec+1);
+		if (err)
+			continue;
 
+		seb->ec += 1;
+		list_del(&seb->u.list);
+		dbg_bld("return PEB %d, EC %d", seb->pnum, seb->ec);
+		return seb;
+	}
+
+	ubi_err("no free eraseblocks");
+	return ERR_PTR(-ENOSPC);
+}
+
+/**
+ * check_corruption - check the data area of PEB.
+ * @ubi: UBI device description object
+ * @vid_hrd: the (corrupted) VID header of this PEB
+ * @pnum: the physical eraseblock number to check
+ *
+ * This is a helper function which is used to distinguish between VID header
+ * corruptions caused by power cuts and other reasons. If the PEB contains only
+ * 0xFF bytes in the data area, the VID header is most probably corrupted
+ * because of a power cut (%0 is returned in this case). Otherwise, it was
+ * probably corrupted for some other reasons (%1 is returned in this case). A
+ * negative error code is returned if a read error occurred.
+ *
+ * If the corruption reason was a power cut, UBI can safely erase this PEB.
+ * Otherwise, it should preserve it to avoid possibly destroying important
+ * information.
+ */
+static int check_corruption(struct ubi_device *ubi, struct ubi_vid_hdr *vid_hdr,
+			    int pnum)
+{
+	int err;
+
+	mutex_lock(&ubi->buf_mutex);
+	memset(ubi->peb_buf1, 0x00, ubi->leb_size);
+
+	err = ubi_io_read(ubi, ubi->peb_buf1, pnum, ubi->leb_start,
+			  ubi->leb_size);
+	if (err == UBI_IO_BITFLIPS || err == -EBADMSG) {
 		/*
-		 * We try to erase the first physical eraseblock from the @head
-		 * list and pick it if we succeed, or try to erase the
-		 * next one if not. And so forth. We don't want to take care
-		 * about bad eraseblocks here - they'll be handled later.
+		 * Bit-flips or integrity errors while reading the data area.
+		 * It is difficult to say for sure what type of corruption is
+		 * this, but presumably a power cut happened while this PEB was
+		 * erased, so it became unstable and corrupted, and should be
+		 * erased.
 		 */
-		list_for_each_entry_safe(seb, tmp_seb, head, u.list) {
-			if (seb->ec == UBI_SCAN_UNKNOWN_EC)
-				seb->ec = si->mean_ec;
+		return 0;
+	}
 
-			err = ubi_scan_erase_peb(ubi, si, seb->pnum, seb->ec+1);
-			if (err)
-				continue;
+	if (err)
+		return err;
 
-			seb->ec += 1;
-			list_del(&seb->u.list);
-			dbg_bld("return PEB %d, EC %d", seb->pnum, seb->ec);
-			return seb;
-		}
+	if (ubi_check_pattern(ubi->peb_buf1, 0xFF, ubi->leb_size)) {
+		mutex_unlock(&ubi->buf_mutex);
+		return 0;
 	}
 
-	ubi_err("no eraseblocks found");
-	return ERR_PTR(-ENOSPC);
+	ubi_err("PEB %d contains corrupted VID header, and the data does not "
+		"contain all 0xFF, this may be a non-UBI PEB or a severe VID "
+		"header corruption which requires manual inspection", pnum);
+	ubi_dbg_dump_vid_hdr(vid_hdr);
+	dbg_msg("hexdump of PEB %d offset %d, length %d",
+		pnum, ubi->leb_start, ubi->leb_size);
+	ubi_dbg_print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
+			       ubi->peb_buf1, ubi->leb_size, 1);
+	mutex_unlock(&ubi->buf_mutex);
+	return 1;
 }
 
 /**
@@ -725,7 +823,7 @@ static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si,
 		      int pnum)
 {
 	long long uninitialized_var(ec);
-	int err, bitflips = 0, vol_id, ec_corr = 0;
+	int err, bitflips = 0, vol_id, ec_err = 0;
 
 	dbg_bld("scan PEB %d", pnum);
 
@@ -746,22 +844,37 @@ static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si,
 	err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
 	if (err < 0)
 		return err;
-	else if (err == UBI_IO_BITFLIPS)
+	switch (err) {
+	case 0:
+		break;
+	case UBI_IO_BITFLIPS:
 		bitflips = 1;
-	else if (err == UBI_IO_PEB_EMPTY)
-		return add_to_list(si, pnum, UBI_SCAN_UNKNOWN_EC, &si->erase);
-	else if (err == UBI_IO_BAD_HDR_READ || err == UBI_IO_BAD_HDR) {
+		break;
+	case UBI_IO_FF:
+		si->empty_peb_count += 1;
+		return add_to_list(si, pnum, UBI_SCAN_UNKNOWN_EC, 0,
+				   &si->erase);
+	case UBI_IO_FF_BITFLIPS:
+		si->empty_peb_count += 1;
+		return add_to_list(si, pnum, UBI_SCAN_UNKNOWN_EC, 1,
+				   &si->erase);
+	case UBI_IO_BAD_HDR_EBADMSG:
+	case UBI_IO_BAD_HDR:
 		/*
 		 * We have to also look at the VID header, possibly it is not
 		 * corrupted. Set %bitflips flag in order to make this PEB be
 		 * moved and EC be re-created.
 		 */
-		ec_corr = err;
+		ec_err = err;
 		ec = UBI_SCAN_UNKNOWN_EC;
 		bitflips = 1;
+		break;
+	default:
+		ubi_err("'ubi_io_read_ec_hdr()' returned unknown code %d", err);
+		return -EINVAL;
 	}
 
-	if (!ec_corr) {
+	if (!ec_err) {
 		int image_seq;
 
 		/* Make sure UBI version is OK */
@@ -814,24 +927,67 @@ static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si,
 	err = ubi_io_read_vid_hdr(ubi, pnum, vidh, 0);
 	if (err < 0)
 		return err;
-	else if (err == UBI_IO_BITFLIPS)
+	switch (err) {
+	case 0:
+		break;
+	case UBI_IO_BITFLIPS:
 		bitflips = 1;
-	else if (err == UBI_IO_BAD_HDR_READ || err == UBI_IO_BAD_HDR ||
-		 (err == UBI_IO_PEB_FREE && ec_corr)) {
-		/* VID header is corrupted */
-		if (err == UBI_IO_BAD_HDR_READ ||
-		    ec_corr == UBI_IO_BAD_HDR_READ)
-			si->read_err_count += 1;
-		err = add_to_list(si, pnum, ec, &si->corr);
+		break;
+	case UBI_IO_BAD_HDR_EBADMSG:
+		if (ec_err == UBI_IO_BAD_HDR_EBADMSG)
+			/*
+			 * Both EC and VID headers are corrupted and were read
+			 * with data integrity error, probably this is a bad
+			 * PEB, bit it is not marked as bad yet. This may also
+			 * be a result of power cut during erasure.
+			 */
+			si->maybe_bad_peb_count += 1;
+	case UBI_IO_BAD_HDR:
+		if (ec_err)
+			/*
+			 * Both headers are corrupted. There is a possibility
+			 * that this a valid UBI PEB which has corresponding
+			 * LEB, but the headers are corrupted. However, it is
+			 * impossible to distinguish it from a PEB which just
+			 * contains garbage because of a power cut during erase
+			 * operation. So we just schedule this PEB for erasure.
+			 */
+			err = 0;
+		else
+			/*
+			 * The EC was OK, but the VID header is corrupted. We
+			 * have to check what is in the data area.
+			 */
+			err = check_corruption(ubi, vidh, pnum);
+
+		if (err < 0)
+			return err;
+		else if (!err)
+			/* This corruption is caused by a power cut */
+			err = add_to_list(si, pnum, ec, 1, &si->erase);
+		else
+			/* This is an unexpected corruption */
+			err = add_corrupted(si, pnum, ec);
 		if (err)
 			return err;
 		goto adjust_mean_ec;
-	} else if (err == UBI_IO_PEB_FREE) {
-		/* No VID header - the physical eraseblock is free */
-		err = add_to_list(si, pnum, ec, &si->free);
+	case UBI_IO_FF_BITFLIPS:
+		err = add_to_list(si, pnum, ec, 1, &si->erase);
 		if (err)
 			return err;
 		goto adjust_mean_ec;
+	case UBI_IO_FF:
+		if (ec_err)
+			err = add_to_list(si, pnum, ec, 1, &si->erase);
+		else
+			err = add_to_list(si, pnum, ec, 0, &si->free);
+		if (err)
+			return err;
+		goto adjust_mean_ec;
+	default:
+		ubi_err("'ubi_io_read_vid_hdr()' returned unknown code %d",
+			err);
+		return -EINVAL;
 	}
 
 	vol_id = be32_to_cpu(vidh->vol_id);
@@ -843,7 +999,7 @@ static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si,
 		case UBI_COMPAT_DELETE:
 			ubi_msg("\"delete\" compatible internal volume %d:%d"
 				" found, will remove it", vol_id, lnum);
-			err = add_to_list(si, pnum, ec, &si->erase);
+			err = add_to_list(si, pnum, ec, 1, &si->erase);
 			if (err)
 				return err;
 			return 0;
@@ -858,7 +1014,7 @@ static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si,
 		case UBI_COMPAT_PRESERVE:
 			ubi_msg("\"preserve\" compatible internal volume %d:%d"
 				" found", vol_id, lnum);
-			err = add_to_list(si, pnum, ec, &si->alien);
+			err = add_to_list(si, pnum, ec, 0, &si->alien);
 			if (err)
 				return err;
 			return 0;
@@ -870,7 +1026,7 @@ static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si,
 		}
 	}
 
-	if (ec_corr)
+	if (ec_err)
 		ubi_warn("valid VID header but corrupted EC header at PEB %d",
 			 pnum);
 	err = ubi_scan_add_used(ubi, si, pnum, ec, vidh, bitflips);
@@ -878,7 +1034,7 @@ static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si,
 		return err;
 
 adjust_mean_ec:
-	if (!ec_corr) {
+	if (!ec_err) {
 		si->ec_sum += ec;
 		si->ec_count += 1;
 		if (ec > si->max_ec)
@@ -904,19 +1060,20 @@ adjust_mean_ec:
 static int check_what_we_have(struct ubi_device *ubi, struct ubi_scan_info *si)
 {
 	struct ubi_scan_leb *seb;
-	int max_corr;
+	int max_corr, peb_count;
 
-	max_corr = ubi->peb_count - si->bad_peb_count - si->alien_peb_count;
-	max_corr = max_corr / 20 ?: 8;
+	peb_count = ubi->peb_count - si->bad_peb_count - si->alien_peb_count;
+	max_corr = peb_count / 20 ?: 8;
 
 	/*
-	 * Few corrupted PEBs are not a problem and may be just a result of
+	 * Few corrupted PEBs is not a problem and may be just a result of
 	 * unclean reboots. However, many of them may indicate some problems
 	 * with the flash HW or driver.
 	 */
-	if (si->corr_peb_count >= 8) {
-		ubi_warn("%d PEBs are corrupted", si->corr_peb_count);
-		printk(KERN_WARNING "corrupted PEBs are:");
+	if (si->corr_peb_count) {
+		ubi_err("%d PEBs are corrupted and preserved",
+			si->corr_peb_count);
+		printk(KERN_ERR "Corrupted PEBs are:");
 		list_for_each_entry(seb, &si->corr, u.list)
 			printk(KERN_CONT " %d", seb->pnum);
 		printk(KERN_CONT "\n");
@@ -931,41 +1088,35 @@ static int check_what_we_have(struct ubi_device *ubi, struct ubi_scan_info *si)
 		}
 	}
 
-	if (si->free_peb_count + si->used_peb_count +
-	    si->alien_peb_count == 0) {
-		/* No UBI-formatted eraseblocks were found */
-		if (si->corr_peb_count == si->read_err_count &&
-		    si->corr_peb_count < 8) {
-			/* No or just few corrupted PEBs, and all of them had a
-			 * read error. We assume that those are bad PEBs, which
-			 * were just not marked as bad so far.
-			 *
-			 * This piece of code basically tries to distinguish
-			 * between the following 2 situations:
-			 *
-			 * 1. Flash is empty, but there are few bad PEBs, which
-			 *    are not marked as bad so far, and which were read
-			 *    with error. We want to go ahead and format this
-			 *    flash. While formating, the faulty PEBs will
-			 *    probably be marked as bad.
-			 *
-			 * 2. Flash probably contains non-UBI data and we do
-			 * not want to format it and destroy possibly needed
-			 * data (e.g., consider the case when the bootloader
-			 * MTD partition was accidentally fed to UBI).
-			 */
+	if (si->empty_peb_count + si->maybe_bad_peb_count == peb_count) {
+		/*
+		 * All PEBs are empty, or almost all - a couple PEBs look like
+		 * they may be bad PEBs which were not marked as bad yet.
+		 *
+		 * This piece of code basically tries to distinguish between
+		 * the following situations:
+		 *
+		 * 1. Flash is empty, but there are few bad PEBs, which are not
+		 *    marked as bad so far, and which were read with error. We
+		 *    want to go ahead and format this flash. While formatting,
+		 *    the faulty PEBs will probably be marked as bad.
+		 *
+		 * 2. Flash contains non-UBI data and we do not want to format
+		 *    it and destroy possibly important information.
+		 */
+		if (si->maybe_bad_peb_count <= 2) {
 			si->is_empty = 1;
 			ubi_msg("empty MTD device detected");
-			get_random_bytes(&ubi->image_seq, sizeof(ubi->image_seq));
+			get_random_bytes(&ubi->image_seq,
+					 sizeof(ubi->image_seq));
 		} else {
-			ubi_err("MTD device possibly contains non-UBI data, "
-				"refusing it");
+			ubi_err("MTD device is not UBI-formatted and possibly "
+				"contains non-UBI data - refusing it");
 			return -EINVAL;
 		}
+
 	}
 
-	if (si->corr_peb_count > 0)
-		ubi_msg("corrupted PEBs will be formatted");
 	return 0;
 }
 
diff --git a/drivers/mtd/ubi/scan.h b/drivers/mtd/ubi/scan.h
index 2576a8d1532..a3264f0bef2 100644
--- a/drivers/mtd/ubi/scan.h
+++ b/drivers/mtd/ubi/scan.h
@@ -30,6 +30,7 @@
  * @pnum: physical eraseblock number
  * @lnum: logical eraseblock number
  * @scrub: if this physical eraseblock needs scrubbing
+ * @copy_flag: this LEB is a copy (@copy_flag is set in VID header of this LEB)
  * @sqnum: sequence number
  * @u: unions RB-tree or @list links
  * @u.rb: link in the per-volume RB-tree of &struct ubi_scan_leb objects
@@ -42,7 +43,8 @@ struct ubi_scan_leb {
 	int ec;
 	int pnum;
 	int lnum;
-	int scrub;
+	unsigned int scrub:1;
+	unsigned int copy_flag:1;
 	unsigned long long sqnum;
 	union {
 		struct rb_node rb;
@@ -91,14 +93,13 @@ struct ubi_scan_volume {
  * @erase: list of physical eraseblocks which have to be erased
  * @alien: list of physical eraseblocks which should not be used by UBI (e.g.,
  *         those belonging to "preserve"-compatible internal volumes)
- * @used_peb_count: count of used PEBs
  * @corr_peb_count: count of PEBs in the @corr list
- * @read_err_count: count of PEBs read with error (%UBI_IO_BAD_HDR_READ was
- *                  returned)
- * @free_peb_count: count of PEBs in the @free list
- * @erase_peb_count: count of PEBs in the @erase list
+ * @empty_peb_count: count of PEBs which are presumably empty (contain only
+ *                   0xFF bytes)
  * @alien_peb_count: count of PEBs in the @alien list
  * @bad_peb_count: count of bad physical eraseblocks
+ * @maybe_bad_peb_count: count of bad physical eraseblocks which are not marked
+ *                       as bad yet, but which look like bad
  * @vols_found: number of volumes found during scanning
  * @highest_vol_id: highest volume ID
  * @is_empty: flag indicating whether the MTD device is empty or not
@@ -119,13 +120,11 @@ struct ubi_scan_info {
 	struct list_head free;
 	struct list_head erase;
 	struct list_head alien;
-	int used_peb_count;
 	int corr_peb_count;
-	int read_err_count;
-	int free_peb_count;
-	int erase_peb_count;
+	int empty_peb_count;
 	int alien_peb_count;
 	int bad_peb_count;
+	int maybe_bad_peb_count;
 	int vols_found;
 	int highest_vol_id;
 	int is_empty;
diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
index 0359e0cce48..0b0149c41fe 100644
--- a/drivers/mtd/ubi/ubi.h
+++ b/drivers/mtd/ubi/ubi.h
@@ -85,21 +85,26 @@
 /*
  * Error codes returned by the I/O sub-system.
  *
- * UBI_IO_PEB_EMPTY: the physical eraseblock is empty, i.e. it contains only
- *                   %0xFF bytes
- * UBI_IO_PEB_FREE: the physical eraseblock is free, i.e. it contains only a
- *                  valid erase counter header, and the rest are %0xFF bytes
+ * UBI_IO_FF: the read region of flash contains only 0xFFs
+ * UBI_IO_FF_BITFLIPS: the same as %UBI_IO_FF, but also also there was a data
+ *                     integrity error reported by the MTD driver
+ *                     (uncorrectable ECC error in case of NAND)
  * UBI_IO_BAD_HDR: the EC or VID header is corrupted (bad magic or CRC)
- * UBI_IO_BAD_HDR_READ: the same as %UBI_IO_BAD_HDR, but also there was a read
- * 			error reported by the flash driver
+ * UBI_IO_BAD_HDR_EBADMSG: the same as %UBI_IO_BAD_HDR, but also there was a
+ *                         data integrity error reported by the MTD driver
+ *                         (uncorrectable ECC error in case of NAND)
  * UBI_IO_BITFLIPS: bit-flips were detected and corrected
+ *
+ * Note, it is probably better to have bit-flip and ebadmsg as flags which can
+ * be or'ed with other error code. But this is a big change because there are
+ * may callers, so it does not worth the risk of introducing a bug
  */
 enum {
-	UBI_IO_PEB_EMPTY = 1,
-	UBI_IO_PEB_FREE,
+	UBI_IO_FF = 1,
+	UBI_IO_FF_BITFLIPS,
 	UBI_IO_BAD_HDR,
-	UBI_IO_BAD_HDR_READ,
-	UBI_IO_BITFLIPS
+	UBI_IO_BAD_HDR_EBADMSG,
+	UBI_IO_BITFLIPS,
 };
 
 /*
@@ -356,6 +361,8 @@ struct ubi_wl_entry;
  * @peb_size: physical eraseblock size
  * @bad_peb_count: count of bad physical eraseblocks
  * @good_peb_count: count of good physical eraseblocks
+ * @corr_peb_count: count of corrupted physical eraseblocks (preserved and not
+ *                  used by UBI)
  * @erroneous_peb_count: count of erroneous physical eraseblocks in @erroneous
  * @max_erroneous: maximum allowed amount of erroneous physical eraseblocks
  * @min_io_size: minimal input/output unit size of the underlying MTD device
@@ -442,6 +449,7 @@ struct ubi_device {
 	int peb_size;
 	int bad_peb_count;
 	int good_peb_count;
+	int corr_peb_count;
 	int erroneous_peb_count;
 	int max_erroneous;
 	int min_io_size;
@@ -506,6 +514,7 @@ int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
 		      int length);
 int ubi_check_volume(struct ubi_device *ubi, int vol_id);
 void ubi_calculate_reserved(struct ubi_device *ubi);
+int ubi_check_pattern(const void *buf, uint8_t patt, int size);
 
 /* eba.c */
 int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c
index e42afab9a9f..c47620dfc72 100644
--- a/drivers/mtd/ubi/vmt.c
+++ b/drivers/mtd/ubi/vmt.c
@@ -261,6 +261,9 @@ int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req)
 	/* Reserve physical eraseblocks */
 	if (vol->reserved_pebs > ubi->avail_pebs) {
 		dbg_err("not enough PEBs, only %d available", ubi->avail_pebs);
+		if (ubi->corr_peb_count)
+			dbg_err("%d PEBs are corrupted and not used",
+				ubi->corr_peb_count);
 		err = -ENOSPC;
 		goto out_unlock;
 	}
@@ -527,6 +530,9 @@ int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs)
 		if (pebs > ubi->avail_pebs) {
 			dbg_err("not enough PEBs: requested %d, available %d",
 				pebs, ubi->avail_pebs);
+			if (ubi->corr_peb_count)
+				dbg_err("%d PEBs are corrupted and not used",
+					ubi->corr_peb_count);
 			spin_unlock(&ubi->volumes_lock);
 			err = -ENOSPC;
 			goto out_free;
diff --git a/drivers/mtd/ubi/vtbl.c b/drivers/mtd/ubi/vtbl.c
index 14c10bed94e..fcdb7f65fe0 100644
--- a/drivers/mtd/ubi/vtbl.c
+++ b/drivers/mtd/ubi/vtbl.c
@@ -366,7 +366,7 @@ write_error:
 		 * Probably this physical eraseblock went bad, try to pick
 		 * another one.
 		 */
-		list_add_tail(&new_seb->u.list, &si->corr);
+		list_add(&new_seb->u.list, &si->erase);
 		goto retry;
 	}
 	kfree(new_seb);
@@ -662,9 +662,13 @@ static int init_volumes(struct ubi_device *ubi, const struct ubi_scan_info *si,
 	ubi->vol_count += 1;
 	vol->ubi = ubi;
 
-	if (reserved_pebs > ubi->avail_pebs)
+	if (reserved_pebs > ubi->avail_pebs) {
 		ubi_err("not enough PEBs, required %d, available %d",
 			reserved_pebs, ubi->avail_pebs);
+		if (ubi->corr_peb_count)
+			ubi_err("%d PEBs are corrupted and not used",
+				ubi->corr_peb_count);
+	}
 	ubi->rsvd_pebs += reserved_pebs;
 	ubi->avail_pebs -= reserved_pebs;
 
@@ -837,7 +841,7 @@ int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_scan_info *si)
 			return PTR_ERR(ubi->vtbl);
 	}
 
-	ubi->avail_pebs = ubi->good_peb_count;
+	ubi->avail_pebs = ubi->good_peb_count - ubi->corr_peb_count;
 
 	/*
 	 * The layout volume is OK, initialize the corresponding in-RAM data
diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
index 97a435672ea..655bbbe415d 100644
--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -745,7 +745,7 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
 
 	err = ubi_io_read_vid_hdr(ubi, e1->pnum, vid_hdr, 0);
 	if (err && err != UBI_IO_BITFLIPS) {
-		if (err == UBI_IO_PEB_FREE) {
+		if (err == UBI_IO_FF) {
 			/*
 			 * We are trying to move PEB without a VID header. UBI
 			 * always write VID headers shortly after the PEB was
@@ -759,6 +759,16 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
 			dbg_wl("PEB %d has no VID header", e1->pnum);
 			protect = 1;
 			goto out_not_moved;
+		} else if (err == UBI_IO_FF_BITFLIPS) {
+			/*
+			 * The same situation as %UBI_IO_FF, but bit-flips were
+			 * detected. It is better to schedule this PEB for
+			 * scrubbing.
+			 */
+			dbg_wl("PEB %d has no VID header but has bit-flips",
+			       e1->pnum);
+			scrubbing = 1;
+			goto out_not_moved;
 		}
 
 		ubi_err("error %d while reading VID header from PEB %d",
@@ -1468,22 +1478,6 @@ int ubi_wl_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si)
 		ubi->lookuptbl[e->pnum] = e;
 	}
 
-	list_for_each_entry(seb, &si->corr, u.list) {
-		cond_resched();
-
-		e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
-		if (!e)
-			goto out_free;
-
-		e->pnum = seb->pnum;
-		e->ec = seb->ec;
-		ubi->lookuptbl[e->pnum] = e;
-		if (schedule_erase(ubi, e, 0)) {
-			kmem_cache_free(ubi_wl_entry_slab, e);
-			goto out_free;
-		}
-	}
-
 	ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
 		ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
 			cond_resched();
@@ -1510,6 +1504,9 @@ int ubi_wl_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si)
 	if (ubi->avail_pebs < WL_RESERVED_PEBS) {
 		ubi_err("no enough physical eraseblocks (%d, need %d)",
 			ubi->avail_pebs, WL_RESERVED_PEBS);
+		if (ubi->corr_peb_count)
+			ubi_err("%d PEBs are corrupted and not used",
+				ubi->corr_peb_count);
 		goto out_free;
 	}
 	ubi->avail_pebs -= WL_RESERVED_PEBS;