Merge branch 'for-next' of git://gitorious.org/usb/usb into usb-next

* 'for-next' of git://gitorious.org/usb/usb: (47 commits)
  usb: musb: Enable DMA mode1 RX for transfers without short packets
  usb: musb: fix build breakage
  usb: gadget: audio: queue wLength-sized requests
  usb: gadget: audio: actually support both speeds
  usb: gadget: storage: make FSG_NUM_BUFFERS variable size
  USB: gadget: storage: remove alignment assumption
  usb: gadget: storage: adapt logic block size to bound block devices
  usb: dwc3: gadget: improve debug on link state change
  usb: dwc3: omap: set idle and standby modes
  usb: dwc3: ep0: introduce ep0_expect_in flag
  usb: dwc3: ep0: giveback requests on stall_and_restart
  usb: dwc3: gadget: drop the useless dma_sync_single* calls
  usb: dwc3: gadget: fix GCTL programming
  usb: dwc3: define ScaleDown macro helper
  usb: dwc3: Fix definition of DWC3_GCTL_U2RSTECN
  usb: dwc3: gadget: do not map/unmap ZLP transfers
  usb: dwc3: omap: fix IRQ handling
  usb: dwc3: omap: change IRQ name to dwc3-omap
  usb: dwc3: add module.h to dwc3-omap.c and core.c
  usb: dwc3: omap: distinguish between SW and HW modes
  ...

5 files changed, 219 insertions, 163 deletions

diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index fe563798389..a60b472a0b3 100644
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -96,6 +96,22 @@ config USB_GADGET_VBUS_DRAW
 	   This value will be used except for system-specific gadget
 	   drivers that have more specific information.
 
+config USB_GADGET_STORAGE_NUM_BUFFERS
+	int "Number of storage pipeline buffers"
+	range 2 4
+	default 2
+	help
+	   Usually 2 buffers are enough to establish a good buffering
+	   pipeline. The number may be increased in order to compensate
+	   for a bursty VFS behaviour. For instance there may be CPU wake up
+	   latencies that makes the VFS to appear bursty in a system with
+	   an CPU on-demand governor. Especially if DMA is doing IO to
+	   offload the CPU. In this case the CPU will go into power
+	   save often and spin up occasionally to move data within VFS.
+	   If selecting USB_GADGET_DEBUG_FILES this value may be set by
+	   a module parameter as well.
+	   If unsure, say 2.
+
 #
 # USB Peripheral Controller Support
 #
diff --git a/drivers/usb/gadget/f_audio.c b/drivers/usb/gadget/f_audio.c
index a9a4eade7e8..ec7ffcd0d0c 100644
--- a/drivers/usb/gadget/f_audio.c
+++ b/drivers/usb/gadget/f_audio.c
@@ -460,7 +460,7 @@ static int audio_set_endpoint_req(struct usb_function *f,
 
 	switch (ctrl->bRequest) {
 	case UAC_SET_CUR:
-		value = 0;
+		value = len;
 		break;
 
 	case UAC_SET_MIN:
@@ -499,7 +499,7 @@ static int audio_get_endpoint_req(struct usb_function *f,
 	case UAC_GET_MIN:
 	case UAC_GET_MAX:
 	case UAC_GET_RES:
-		value = 3;
+		value = len;
 		break;
 	case UAC_GET_MEM:
 		break;
@@ -681,17 +681,18 @@ f_audio_bind(struct usb_configuration *c, struct usb_function *f)
 
 	status = -ENOMEM;
 
-	/* supcard all relevant hardware speeds... we expect that when
+	/* copy descriptors, and track endpoint copies */
+	f->descriptors = usb_copy_descriptors(f_audio_desc);
+
+	/*
+	 * support all relevant hardware speeds... we expect that when
 	 * hardware is dual speed, all bulk-capable endpoints work at
 	 * both speeds
 	 */
-
-	/* copy descriptors, and track endpoint copies */
 	if (gadget_is_dualspeed(c->cdev->gadget)) {
 		c->highspeed = true;
 		f->hs_descriptors = usb_copy_descriptors(f_audio_desc);
-	} else
-		f->descriptors = usb_copy_descriptors(f_audio_desc);
+	}
 
 	return 0;
 
diff --git a/drivers/usb/gadget/f_mass_storage.c b/drivers/usb/gadget/f_mass_storage.c
index 4ce3decda1d..75694147314 100644
--- a/drivers/usb/gadget/f_mass_storage.c
+++ b/drivers/usb/gadget/f_mass_storage.c
@@ -112,8 +112,7 @@
  * is not loaded (an empty string as "filename" in the fsg_config
  * structure causes error).  The CD-ROM emulation includes a single
  * data track and no audio tracks; hence there need be only one
- * backing file per LUN.  Note also that the CD-ROM block length is
- * set to 512 rather than the more common value 2048.
+ * backing file per LUN.
  *
  *
  * MSF includes support for module parameters.  If gadget using it
@@ -363,7 +362,7 @@ struct fsg_common {
 
 	struct fsg_buffhd	*next_buffhd_to_fill;
 	struct fsg_buffhd	*next_buffhd_to_drain;
-	struct fsg_buffhd	buffhds[FSG_NUM_BUFFERS];
+	struct fsg_buffhd	*buffhds;
 
 	int			cmnd_size;
 	u8			cmnd[MAX_COMMAND_SIZE];
@@ -745,7 +744,6 @@ static int do_read(struct fsg_common *common)
 	u32			amount_left;
 	loff_t			file_offset, file_offset_tmp;
 	unsigned int		amount;
-	unsigned int		partial_page;
 	ssize_t			nread;
 
 	/*
@@ -771,7 +769,7 @@ static int do_read(struct fsg_common *common)
 		curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
 		return -EINVAL;
 	}
-	file_offset = ((loff_t) lba) << 9;
+	file_offset = ((loff_t) lba) << curlun->blkbits;
 
 	/* Carry out the file reads */
 	amount_left = common->data_size_from_cmnd;
@@ -784,18 +782,10 @@ static int do_read(struct fsg_common *common)
 		 * Try to read the remaining amount.
 		 * But don't read more than the buffer size.
 		 * And don't try to read past the end of the file.
-		 * Finally, if we're not at a page boundary, don't read past
-		 *	the next page.
-		 * If this means reading 0 then we were asked to read past
-		 *	the end of file.
 		 */
 		amount = min(amount_left, FSG_BUFLEN);
 		amount = min((loff_t)amount,
 			     curlun->file_length - file_offset);
-		partial_page = file_offset & (PAGE_CACHE_SIZE - 1);
-		if (partial_page > 0)
-			amount = min(amount, (unsigned int)PAGE_CACHE_SIZE -
-					     partial_page);
 
 		/* Wait for the next buffer to become available */
 		bh = common->next_buffhd_to_fill;
@@ -812,7 +802,8 @@ static int do_read(struct fsg_common *common)
 		if (amount == 0) {
 			curlun->sense_data =
 					SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
-			curlun->sense_data_info = file_offset >> 9;
+			curlun->sense_data_info =
+					file_offset >> curlun->blkbits;
 			curlun->info_valid = 1;
 			bh->inreq->length = 0;
 			bh->state = BUF_STATE_FULL;
@@ -835,18 +826,25 @@ static int do_read(struct fsg_common *common)
 		} else if (nread < amount) {
 			LDBG(curlun, "partial file read: %d/%u\n",
 			     (int)nread, amount);
-			nread -= (nread & 511);	/* Round down to a block */
+			nread = round_down(nread, curlun->blksize);
 		}
 		file_offset  += nread;
 		amount_left  -= nread;
 		common->residue -= nread;
+
+		/*
+		 * Except at the end of the transfer, nread will be
+		 * equal to the buffer size, which is divisible by the
+		 * bulk-in maxpacket size.
+		 */
 		bh->inreq->length = nread;
 		bh->state = BUF_STATE_FULL;
 
 		/* If an error occurred, report it and its position */
 		if (nread < amount) {
 			curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
-			curlun->sense_data_info = file_offset >> 9;
+			curlun->sense_data_info =
+					file_offset >> curlun->blkbits;
 			curlun->info_valid = 1;
 			break;
 		}
@@ -877,7 +875,6 @@ static int do_write(struct fsg_common *common)
 	u32			amount_left_to_req, amount_left_to_write;
 	loff_t			usb_offset, file_offset, file_offset_tmp;
 	unsigned int		amount;
-	unsigned int		partial_page;
 	ssize_t			nwritten;
 	int			rc;
 
@@ -921,7 +918,7 @@ static int do_write(struct fsg_common *common)
 
 	/* Carry out the file writes */
 	get_some_more = 1;
-	file_offset = usb_offset = ((loff_t) lba) << 9;
+	file_offset = usb_offset = ((loff_t) lba) << curlun->blkbits;
 	amount_left_to_req = common->data_size_from_cmnd;
 	amount_left_to_write = common->data_size_from_cmnd;
 
@@ -933,41 +930,21 @@ static int do_write(struct fsg_common *common)
 
 			/*
 			 * Figure out how much we want to get:
-			 * Try to get the remaining amount.
-			 * But don't get more than the buffer size.
-			 * And don't try to go past the end of the file.
-			 * If we're not at a page boundary,
-			 *	don't go past the next page.
-			 * If this means getting 0, then we were asked
-			 *	to write past the end of file.
-			 * Finally, round down to a block boundary.
+			 * Try to get the remaining amount,
+			 * but not more than the buffer size.
 			 */
 			amount = min(amount_left_to_req, FSG_BUFLEN);
-			amount = min((loff_t)amount,
-				     curlun->file_length - usb_offset);
-			partial_page = usb_offset & (PAGE_CACHE_SIZE - 1);
-			if (partial_page > 0)
-				amount = min(amount,
-	(unsigned int)PAGE_CACHE_SIZE - partial_page);
-
-			if (amount == 0) {
+
+			/* Beyond the end of the backing file? */
+			if (usb_offset >= curlun->file_length) {
 				get_some_more = 0;
 				curlun->sense_data =
 					SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
-				curlun->sense_data_info = usb_offset >> 9;
+				curlun->sense_data_info =
+					usb_offset >> curlun->blkbits;
 				curlun->info_valid = 1;
 				continue;
 			}
-			amount -= amount & 511;
-			if (amount == 0) {
-
-				/*
-				 * Why were we were asked to transfer a
-				 * partial block?
-				 */
-				get_some_more = 0;
-				continue;
-			}
 
 			/* Get the next buffer */
 			usb_offset += amount;
@@ -977,8 +954,9 @@ static int do_write(struct fsg_common *common)
 				get_some_more = 0;
 
 			/*
-			 * amount is always divisible by 512, hence by
-			 * the bulk-out maxpacket size
+			 * Except at the end of the transfer, amount will be
+			 * equal to the buffer size, which is divisible by
+			 * the bulk-out maxpacket size.
 			 */
 			bh->outreq->length = amount;
 			bh->bulk_out_intended_length = amount;
@@ -1002,7 +980,8 @@ static int do_write(struct fsg_common *common)
 			/* Did something go wrong with the transfer? */
 			if (bh->outreq->status != 0) {
 				curlun->sense_data = SS_COMMUNICATION_FAILURE;
-				curlun->sense_data_info = file_offset >> 9;
+				curlun->sense_data_info =
+					file_offset >> curlun->blkbits;
 				curlun->info_valid = 1;
 				break;
 			}
@@ -1016,6 +995,11 @@ static int do_write(struct fsg_common *common)
 				amount = curlun->file_length - file_offset;
 			}
 
+			/* Don't write a partial block */
+			amount = round_down(amount, curlun->blksize);
+			if (amount == 0)
+				goto empty_write;
+
 			/* Perform the write */
 			file_offset_tmp = file_offset;
 			nwritten = vfs_write(curlun->filp,
@@ -1033,8 +1017,7 @@ static int do_write(struct fsg_common *common)
 			} else if (nwritten < amount) {
 				LDBG(curlun, "partial file write: %d/%u\n",
 				     (int)nwritten, amount);
-				nwritten -= (nwritten & 511);
-				/* Round down to a block */
+				nwritten = round_down(nwritten, curlun->blksize);
 			}
 			file_offset += nwritten;
 			amount_left_to_write -= nwritten;
@@ -1043,11 +1026,13 @@ static int do_write(struct fsg_common *common)
 			/* If an error occurred, report it and its position */
 			if (nwritten < amount) {
 				curlun->sense_data = SS_WRITE_ERROR;
-				curlun->sense_data_info = file_offset >> 9;
+				curlun->sense_data_info =
+					file_offset >> curlun->blkbits;
 				curlun->info_valid = 1;
 				break;
 			}
 
+ empty_write:
 			/* Did the host decide to stop early? */
 			if (bh->outreq->actual != bh->outreq->length) {
 				common->short_packet_received = 1;
@@ -1129,8 +1114,8 @@ static int do_verify(struct fsg_common *common)
 		return -EIO;		/* No default reply */
 
 	/* Prepare to carry out the file verify */
-	amount_left = verification_length << 9;
-	file_offset = ((loff_t) lba) << 9;
+	amount_left = verification_length << curlun->blkbits;
+	file_offset = ((loff_t) lba) << curlun->blkbits;
 
 	/* Write out all the dirty buffers before invalidating them */
 	fsg_lun_fsync_sub(curlun);
@@ -1148,8 +1133,6 @@ static int do_verify(struct fsg_common *common)
 		 * Try to read the remaining amount, but not more than
 		 * the buffer size.
 		 * And don't try to read past the end of the file.
-		 * If this means reading 0 then we were asked to read
-		 * past the end of file.
 		 */
 		amount = min(amount_left, FSG_BUFLEN);
 		amount = min((loff_t)amount,
@@ -1157,7 +1140,8 @@ static int do_verify(struct fsg_common *common)
 		if (amount == 0) {
 			curlun->sense_data =
 					SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
-			curlun->sense_data_info = file_offset >> 9;
+			curlun->sense_data_info =
+				file_offset >> curlun->blkbits;
 			curlun->info_valid = 1;
 			break;
 		}
@@ -1179,11 +1163,12 @@ static int do_verify(struct fsg_common *common)
 		} else if (nread < amount) {
 			LDBG(curlun, "partial file verify: %d/%u\n",
 			     (int)nread, amount);
-			nread -= nread & 511;	/* Round down to a sector */
+			nread = round_down(nread, curlun->blksize);
 		}
 		if (nread == 0) {
 			curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
-			curlun->sense_data_info = file_offset >> 9;
+			curlun->sense_data_info =
+				file_offset >> curlun->blkbits;
 			curlun->info_valid = 1;
 			break;
 		}
@@ -1289,7 +1274,7 @@ static int do_read_capacity(struct fsg_common *common, struct fsg_buffhd *bh)
 
 	put_unaligned_be32(curlun->num_sectors - 1, &buf[0]);
 						/* Max logical block */
-	put_unaligned_be32(512, &buf[4]);	/* Block length */
+	put_unaligned_be32(curlun->blksize, &buf[4]);/* Block length */
 	return 8;
 }
 
@@ -1527,7 +1512,7 @@ static int do_read_format_capacities(struct fsg_common *common,
 
 	put_unaligned_be32(curlun->num_sectors, &buf[0]);
 						/* Number of blocks */
-	put_unaligned_be32(512, &buf[4]);	/* Block length */
+	put_unaligned_be32(curlun->blksize, &buf[4]);/* Block length */
 	buf[4] = 0x02;				/* Current capacity */
 	return 12;
 }
@@ -1623,7 +1608,8 @@ static int throw_away_data(struct fsg_common *common)
 			amount = min(common->usb_amount_left, FSG_BUFLEN);
 
 			/*
-			 * amount is always divisible by 512, hence by
+			 * Except at the end of the transfer, amount will be
+			 * equal to the buffer size, which is divisible by
 			 * the bulk-out maxpacket size.
 			 */
 			bh->outreq->length = amount;
@@ -2022,7 +2008,8 @@ static int do_scsi_command(struct fsg_common *common)
 
 	case READ_6:
 		i = common->cmnd[4];
-		common->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
+		common->data_size_from_cmnd = (i == 0 ? 256 : i) <<
+				common->curlun->blkbits;
 		reply = check_command(common, 6, DATA_DIR_TO_HOST,
 				      (7<<1) | (1<<4), 1,
 				      "READ(6)");
@@ -2032,7 +2019,8 @@ static int do_scsi_command(struct fsg_common *common)
 
 	case READ_10:
 		common->data_size_from_cmnd =
-				get_unaligned_be16(&common->cmnd[7]) << 9;
+				get_unaligned_be16(&common->cmnd[7]) <<
+						common->curlun->blkbits;
 		reply = check_command(common, 10, DATA_DIR_TO_HOST,
 				      (1<<1) | (0xf<<2) | (3<<7), 1,
 				      "READ(10)");
@@ -2042,7 +2030,8 @@ static int do_scsi_command(struct fsg_common *common)
 
 	case READ_12:
 		common->data_size_from_cmnd =
-				get_unaligned_be32(&common->cmnd[6]) << 9;
+				get_unaligned_be32(&common->cmnd[6]) <<
+						common->curlun->blkbits;
 		reply = check_command(common, 12, DATA_DIR_TO_HOST,
 				      (1<<1) | (0xf<<2) | (0xf<<6), 1,
 				      "READ(12)");
@@ -2142,7 +2131,8 @@ static int do_scsi_command(struct fsg_common *common)
 
 	case WRITE_6:
 		i = common->cmnd[4];
-		common->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
+		common->data_size_from_cmnd = (i == 0 ? 256 : i) <<
+					common->curlun->blkbits;
 		reply = check_command(common, 6, DATA_DIR_FROM_HOST,
 				      (7<<1) | (1<<4), 1,
 				      "WRITE(6)");
@@ -2152,7 +2142,8 @@ static int do_scsi_command(struct fsg_common *common)
 
 	case WRITE_10:
 		common->data_size_from_cmnd =
-				get_unaligned_be16(&common->cmnd[7]) << 9;
+				get_unaligned_be16(&common->cmnd[7]) <<
+						common->curlun->blkbits;
 		reply = check_command(common, 10, DATA_DIR_FROM_HOST,
 				      (1<<1) | (0xf<<2) | (3<<7), 1,
 				      "WRITE(10)");
@@ -2162,7 +2153,8 @@ static int do_scsi_command(struct fsg_common *common)
 
 	case WRITE_12:
 		common->data_size_from_cmnd =
-				get_unaligned_be32(&common->cmnd[6]) << 9;
+				get_unaligned_be32(&common->cmnd[6]) <<
+						common->curlun->blkbits;
 		reply = check_command(common, 12, DATA_DIR_FROM_HOST,
 				      (1<<1) | (0xf<<2) | (0xf<<6), 1,
 				      "WRITE(12)");
@@ -2348,7 +2340,7 @@ reset:
 	if (common->fsg) {
 		fsg = common->fsg;
 
-		for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
+		for (i = 0; i < fsg_num_buffers; ++i) {
 			struct fsg_buffhd *bh = &common->buffhds[i];
 
 			if (bh->inreq) {
@@ -2405,7 +2397,7 @@ reset:
 	clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
 
 	/* Allocate the requests */
-	for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
+	for (i = 0; i < fsg_num_buffers; ++i) {
 		struct fsg_buffhd	*bh = &common->buffhds[i];
 
 		rc = alloc_request(common, fsg->bulk_in, &bh->inreq);
@@ -2474,7 +2466,7 @@ static void handle_exception(struct fsg_common *common)
 
 	/* Cancel all the pending transfers */
 	if (likely(common->fsg)) {
-		for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
+		for (i = 0; i < fsg_num_buffers; ++i) {
 			bh = &common->buffhds[i];
 			if (bh->inreq_busy)
 				usb_ep_dequeue(common->fsg->bulk_in, bh->inreq);
@@ -2486,7 +2478,7 @@ static void handle_exception(struct fsg_common *common)
 		/* Wait until everything is idle */
 		for (;;) {
 			int num_active = 0;
-			for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
+			for (i = 0; i < fsg_num_buffers; ++i) {
 				bh = &common->buffhds[i];
 				num_active += bh->inreq_busy + bh->outreq_busy;
 			}
@@ -2509,7 +2501,7 @@ static void handle_exception(struct fsg_common *common)
 	 */
 	spin_lock_irq(&common->lock);
 
-	for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
+	for (i = 0; i < fsg_num_buffers; ++i) {
 		bh = &common->buffhds[i];
 		bh->state = BUF_STATE_EMPTY;
 	}
@@ -2718,6 +2710,10 @@ static struct fsg_common *fsg_common_init(struct fsg_common *common,
 	int nluns, i, rc;
 	char *pathbuf;
 
+	rc = fsg_num_buffers_validate();
+	if (rc != 0)
+		return ERR_PTR(rc);
+
 	/* Find out how many LUNs there should be */
 	nluns = cfg->nluns;
 	if (nluns < 1 || nluns > FSG_MAX_LUNS) {
@@ -2736,6 +2732,14 @@ static struct fsg_common *fsg_common_init(struct fsg_common *common,
 		common->free_storage_on_release = 0;
 	}
 
+	common->buffhds = kcalloc(fsg_num_buffers,
+				  sizeof *(common->buffhds), GFP_KERNEL);
+	if (!common->buffhds) {
+		if (common->free_storage_on_release)
+			kfree(common);
+		return ERR_PTR(-ENOMEM);
+	}
+
 	common->ops = cfg->ops;
 	common->private_data = cfg->private_data;
 
@@ -2813,7 +2817,7 @@ static struct fsg_common *fsg_common_init(struct fsg_common *common,
 
 	/* Data buffers cyclic list */
 	bh = common->buffhds;
-	i = FSG_NUM_BUFFERS;
+	i = fsg_num_buffers;
 	goto buffhds_first_it;
 	do {
 		bh->next = bh + 1;
@@ -2939,12 +2943,13 @@ static void fsg_common_release(struct kref *ref)
 
 	{
 		struct fsg_buffhd *bh = common->buffhds;
-		unsigned i = FSG_NUM_BUFFERS;
+		unsigned i = fsg_num_buffers;
 		do {
 			kfree(bh->buf);
 		} while (++bh, --i);
 	}
 
+	kfree(common->buffhds);
 	if (common->free_storage_on_release)
 		kfree(common);
 }
diff --git a/drivers/usb/gadget/file_storage.c b/drivers/usb/gadget/file_storage.c
index 4ac8084b579..12ac30b21ba 100644
--- a/drivers/usb/gadget/file_storage.c
+++ b/drivers/usb/gadget/file_storage.c
@@ -69,8 +69,7 @@
  * each LUN would be settable independently as a disk drive or a CD-ROM
  * drive, but currently all LUNs have to be the same type.  The CD-ROM
  * emulation includes a single data track and no audio tracks; hence there
- * need be only one backing file per LUN.  Note also that the CD-ROM block
- * length is set to 512 rather than the more common value 2048.
+ * need be only one backing file per LUN.
  *
  * Requirements are modest; only a bulk-in and a bulk-out endpoint are
  * needed (an interrupt-out endpoint is also needed for CBI).  The memory
@@ -461,7 +460,6 @@ struct fsg_dev {
 
 	struct fsg_buffhd	*next_buffhd_to_fill;
 	struct fsg_buffhd	*next_buffhd_to_drain;
-	struct fsg_buffhd	buffhds[FSG_NUM_BUFFERS];
 
 	int			thread_wakeup_needed;
 	struct completion	thread_notifier;
@@ -488,6 +486,8 @@ struct fsg_dev {
 	unsigned int		nluns;
 	struct fsg_lun		*luns;
 	struct fsg_lun		*curlun;
+	/* Must be the last entry */
+	struct fsg_buffhd	buffhds[];
 };
 
 typedef void (*fsg_routine_t)(struct fsg_dev *);
@@ -1136,7 +1136,6 @@ static int do_read(struct fsg_dev *fsg)
 	u32			amount_left;
 	loff_t			file_offset, file_offset_tmp;
 	unsigned int		amount;
-	unsigned int		partial_page;
 	ssize_t			nread;
 
 	/* Get the starting Logical Block Address and check that it's
@@ -1158,7 +1157,7 @@ static int do_read(struct fsg_dev *fsg)
 		curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
 		return -EINVAL;
 	}
-	file_offset = ((loff_t) lba) << 9;
+	file_offset = ((loff_t) lba) << curlun->blkbits;
 
 	/* Carry out the file reads */
 	amount_left = fsg->data_size_from_cmnd;
@@ -1171,17 +1170,10 @@ static int do_read(struct fsg_dev *fsg)
 		 * Try to read the remaining amount.
 		 * But don't read more than the buffer size.
 		 * And don't try to read past the end of the file.
-		 * Finally, if we're not at a page boundary, don't read past
-		 *	the next page.
-		 * If this means reading 0 then we were asked to read past
-		 *	the end of file. */
+		 */
 		amount = min((unsigned int) amount_left, mod_data.buflen);
 		amount = min((loff_t) amount,
 				curlun->file_length - file_offset);
-		partial_page = file_offset & (PAGE_CACHE_SIZE - 1);
-		if (partial_page > 0)
-			amount = min(amount, (unsigned int) PAGE_CACHE_SIZE -
-					partial_page);
 
 		/* Wait for the next buffer to become available */
 		bh = fsg->next_buffhd_to_fill;
@@ -1196,7 +1188,7 @@ static int do_read(struct fsg_dev *fsg)
 		if (amount == 0) {
 			curlun->sense_data =
 					SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
-			curlun->sense_data_info = file_offset >> 9;
+			curlun->sense_data_info = file_offset >> curlun->blkbits;
 			curlun->info_valid = 1;
 			bh->inreq->length = 0;
 			bh->state = BUF_STATE_FULL;
@@ -1221,18 +1213,23 @@ static int do_read(struct fsg_dev *fsg)
 		} else if (nread < amount) {
 			LDBG(curlun, "partial file read: %d/%u\n",
 					(int) nread, amount);
-			nread -= (nread & 511);	// Round down to a block
+			nread = round_down(nread, curlun->blksize);
 		}
 		file_offset  += nread;
 		amount_left  -= nread;
 		fsg->residue -= nread;
+
+		/* Except at the end of the transfer, nread will be
+		 * equal to the buffer size, which is divisible by the
+		 * bulk-in maxpacket size.
+		 */
 		bh->inreq->length = nread;
 		bh->state = BUF_STATE_FULL;
 
 		/* If an error occurred, report it and its position */
 		if (nread < amount) {
 			curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
-			curlun->sense_data_info = file_offset >> 9;
+			curlun->sense_data_info = file_offset >> curlun->blkbits;
 			curlun->info_valid = 1;
 			break;
 		}
@@ -1262,7 +1259,6 @@ static int do_write(struct fsg_dev *fsg)
 	u32			amount_left_to_req, amount_left_to_write;
 	loff_t			usb_offset, file_offset, file_offset_tmp;
 	unsigned int		amount;
-	unsigned int		partial_page;
 	ssize_t			nwritten;
 	int			rc;
 
@@ -1303,7 +1299,7 @@ static int do_write(struct fsg_dev *fsg)
 
 	/* Carry out the file writes */
 	get_some_more = 1;
-	file_offset = usb_offset = ((loff_t) lba) << 9;
+	file_offset = usb_offset = ((loff_t) lba) << curlun->blkbits;
 	amount_left_to_req = amount_left_to_write = fsg->data_size_from_cmnd;
 
 	while (amount_left_to_write > 0) {
@@ -1313,38 +1309,20 @@ static int do_write(struct fsg_dev *fsg)
 		if (bh->state == BUF_STATE_EMPTY && get_some_more) {
 
 			/* Figure out how much we want to get:
-			 * Try to get the remaining amount.
-			 * But don't get more than the buffer size.
-			 * And don't try to go past the end of the file.
-			 * If we're not at a page boundary,
-			 *	don't go past the next page.
-			 * If this means getting 0, then we were asked
-			 *	to write past the end of file.
-			 * Finally, round down to a block boundary. */
+			 * Try to get the remaining amount,
+			 * but not more than the buffer size.
+			 */
 			amount = min(amount_left_to_req, mod_data.buflen);
-			amount = min((loff_t) amount, curlun->file_length -
-					usb_offset);
-			partial_page = usb_offset & (PAGE_CACHE_SIZE - 1);
-			if (partial_page > 0)
-				amount = min(amount,
-	(unsigned int) PAGE_CACHE_SIZE - partial_page);
-
-			if (amount == 0) {
+
+			/* Beyond the end of the backing file? */
+			if (usb_offset >= curlun->file_length) {
 				get_some_more = 0;
 				curlun->sense_data =
 					SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
-				curlun->sense_data_info = usb_offset >> 9;
+				curlun->sense_data_info = usb_offset >> curlun->blkbits;
 				curlun->info_valid = 1;
 				continue;
 			}
-			amount -= (amount & 511);
-			if (amount == 0) {
-
-				/* Why were we were asked to transfer a
-				 * partial block? */
-				get_some_more = 0;
-				continue;
-			}
 
 			/* Get the next buffer */
 			usb_offset += amount;
@@ -1353,8 +1331,10 @@ static int do_write(struct fsg_dev *fsg)
 			if (amount_left_to_req == 0)
 				get_some_more = 0;
 
-			/* amount is always divisible by 512, hence by
-			 * the bulk-out maxpacket size */
+			/* Except at the end of the transfer, amount will be
+			 * equal to the buffer size, which is divisible by
+			 * the bulk-out maxpacket size.
+			 */
 			bh->outreq->length = bh->bulk_out_intended_length =
 					amount;
 			bh->outreq->short_not_ok = 1;
@@ -1376,7 +1356,7 @@ static int do_write(struct fsg_dev *fsg)
 			/* Did something go wrong with the transfer? */
 			if (bh->outreq->status != 0) {
 				curlun->sense_data = SS_COMMUNICATION_FAILURE;
-				curlun->sense_data_info = file_offset >> 9;
+				curlun->sense_data_info = file_offset >> curlun->blkbits;
 				curlun->info_valid = 1;
 				break;
 			}
@@ -1390,6 +1370,11 @@ static int do_write(struct fsg_dev *fsg)
 				amount = curlun->file_length - file_offset;
 			}
 
+			/* Don't write a partial block */
+			amount = round_down(amount, curlun->blksize);
+			if (amount == 0)
+				goto empty_write;
+
 			/* Perform the write */
 			file_offset_tmp = file_offset;
 			nwritten = vfs_write(curlun->filp,
@@ -1408,8 +1393,7 @@ static int do_write(struct fsg_dev *fsg)
 			} else if (nwritten < amount) {
 				LDBG(curlun, "partial file write: %d/%u\n",
 						(int) nwritten, amount);
-				nwritten -= (nwritten & 511);
-						// Round down to a block
+				nwritten = round_down(nwritten, curlun->blksize);
 			}
 			file_offset += nwritten;
 			amount_left_to_write -= nwritten;
@@ -1418,11 +1402,12 @@ static int do_write(struct fsg_dev *fsg)
 			/* If an error occurred, report it and its position */
 			if (nwritten < amount) {
 				curlun->sense_data = SS_WRITE_ERROR;
-				curlun->sense_data_info = file_offset >> 9;
+				curlun->sense_data_info = file_offset >> curlun->blkbits;
 				curlun->info_valid = 1;
 				break;
 			}
 
+ empty_write:
 			/* Did the host decide to stop early? */
 			if (bh->outreq->actual != bh->outreq->length) {
 				fsg->short_packet_received = 1;
@@ -1500,8 +1485,8 @@ static int do_verify(struct fsg_dev *fsg)
 		return -EIO;		// No default reply
 
 	/* Prepare to carry out the file verify */
-	amount_left = verification_length << 9;
-	file_offset = ((loff_t) lba) << 9;
+	amount_left = verification_length << curlun->blkbits;
+	file_offset = ((loff_t) lba) << curlun->blkbits;
 
 	/* Write out all the dirty buffers before invalidating them */
 	fsg_lun_fsync_sub(curlun);
@@ -1519,15 +1504,14 @@ static int do_verify(struct fsg_dev *fsg)
 		 * Try to read the remaining amount, but not more than
 		 * the buffer size.
 		 * And don't try to read past the end of the file.
-		 * If this means reading 0 then we were asked to read
-		 * past the end of file. */
+		 */
 		amount = min((unsigned int) amount_left, mod_data.buflen);
 		amount = min((loff_t) amount,
 				curlun->file_length - file_offset);
 		if (amount == 0) {
 			curlun->sense_data =
 					SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
-			curlun->sense_data_info = file_offset >> 9;
+			curlun->sense_data_info = file_offset >> curlun->blkbits;
 			curlun->info_valid = 1;
 			break;
 		}
@@ -1550,11 +1534,11 @@ static int do_verify(struct fsg_dev *fsg)
 		} else if (nread < amount) {
 			LDBG(curlun, "partial file verify: %d/%u\n",
 					(int) nread, amount);
-			nread -= (nread & 511);	// Round down to a sector
+			nread = round_down(nread, curlun->blksize);
 		}
 		if (nread == 0) {
 			curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
-			curlun->sense_data_info = file_offset >> 9;
+			curlun->sense_data_info = file_offset >> curlun->blkbits;
 			curlun->info_valid = 1;
 			break;
 		}
@@ -1668,7 +1652,7 @@ static int do_read_capacity(struct fsg_dev *fsg, struct fsg_buffhd *bh)
 
 	put_unaligned_be32(curlun->num_sectors - 1, &buf[0]);
 						/* Max logical block */
-	put_unaligned_be32(512, &buf[4]);	/* Block length */
+	put_unaligned_be32(curlun->blksize, &buf[4]);	/* Block length */
 	return 8;
 }
 
@@ -1890,7 +1874,7 @@ static int do_read_format_capacities(struct fsg_dev *fsg,
 
 	put_unaligned_be32(curlun->num_sectors, &buf[0]);
 						/* Number of blocks */
-	put_unaligned_be32(512, &buf[4]);	/* Block length */
+	put_unaligned_be32(curlun->blksize, &buf[4]);	/* Block length */
 	buf[4] = 0x02;				/* Current capacity */
 	return 12;
 }
@@ -1983,8 +1967,10 @@ static int throw_away_data(struct fsg_dev *fsg)
 			amount = min(fsg->usb_amount_left,
 					(u32) mod_data.buflen);
 
-			/* amount is always divisible by 512, hence by
-			 * the bulk-out maxpacket size */
+			/* Except at the end of the transfer, amount will be
+			 * equal to the buffer size, which is divisible by
+			 * the bulk-out maxpacket size.
+			 */
 			bh->outreq->length = bh->bulk_out_intended_length =
 					amount;
 			bh->outreq->short_not_ok = 1;
@@ -2415,7 +2401,7 @@ static int do_scsi_command(struct fsg_dev *fsg)
 
 	case READ_6:
 		i = fsg->cmnd[4];
-		fsg->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
+		fsg->data_size_from_cmnd = (i == 0 ? 256 : i) << fsg->curlun->blkbits;
 		if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
 				(7<<1) | (1<<4), 1,
 				"READ(6)")) == 0)
@@ -2424,7 +2410,7 @@ static int do_scsi_command(struct fsg_dev *fsg)
 
 	case READ_10:
 		fsg->data_size_from_cmnd =
-				get_unaligned_be16(&fsg->cmnd[7]) << 9;
+				get_unaligned_be16(&fsg->cmnd[7]) << fsg->curlun->blkbits;
 		if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
 				(1<<1) | (0xf<<2) | (3<<7), 1,
 				"READ(10)")) == 0)
@@ -2433,7 +2419,7 @@ static int do_scsi_command(struct fsg_dev *fsg)
 
 	case READ_12:
 		fsg->data_size_from_cmnd =
-				get_unaligned_be32(&fsg->cmnd[6]) << 9;
+				get_unaligned_be32(&fsg->cmnd[6]) << fsg->curlun->blkbits;
 		if ((reply = check_command(fsg, 12, DATA_DIR_TO_HOST,
 				(1<<1) | (0xf<<2) | (0xf<<6), 1,
 				"READ(12)")) == 0)
@@ -2519,7 +2505,7 @@ static int do_scsi_command(struct fsg_dev *fsg)
 
 	case WRITE_6:
 		i = fsg->cmnd[4];
-		fsg->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
+		fsg->data_size_from_cmnd = (i == 0 ? 256 : i) << fsg->curlun->blkbits;
 		if ((reply = check_command(fsg, 6, DATA_DIR_FROM_HOST,
 				(7<<1) | (1<<4), 1,
 				"WRITE(6)")) == 0)
@@ -2528,7 +2514,7 @@ static int do_scsi_command(struct fsg_dev *fsg)
 
 	case WRITE_10:
 		fsg->data_size_from_cmnd =
-				get_unaligned_be16(&fsg->cmnd[7]) << 9;
+				get_unaligned_be16(&fsg->cmnd[7]) << fsg->curlun->blkbits;
 		if ((reply = check_command(fsg, 10, DATA_DIR_FROM_HOST,
 				(1<<1) | (0xf<<2) | (3<<7), 1,
 				"WRITE(10)")) == 0)
@@ -2537,7 +2523,7 @@ static int do_scsi_command(struct fsg_dev *fsg)
 
 	case WRITE_12:
 		fsg->data_size_from_cmnd =
-				get_unaligned_be32(&fsg->cmnd[6]) << 9;
+				get_unaligned_be32(&fsg->cmnd[6]) << fsg->curlun->blkbits;
 		if ((reply = check_command(fsg, 12, DATA_DIR_FROM_HOST,
 				(1<<1) | (0xf<<2) | (0xf<<6), 1,
 				"WRITE(12)")) == 0)
@@ -2752,7 +2738,7 @@ static int do_set_interface(struct fsg_dev *fsg, int altsetting)
 
 reset:
 	/* Deallocate the requests */
-	for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
+	for (i = 0; i < fsg_num_buffers; ++i) {
 		struct fsg_buffhd *bh = &fsg->buffhds[i];
 
 		if (bh->inreq) {
@@ -2813,7 +2799,7 @@ reset:
 	}
 
 	/* Allocate the requests */
-	for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
+	for (i = 0; i < fsg_num_buffers; ++i) {
 		struct fsg_buffhd	*bh = &fsg->buffhds[i];
 
 		if ((rc = alloc_request(fsg, fsg->bulk_in, &bh->inreq)) != 0)
@@ -2902,7 +2888,7 @@ static void handle_exception(struct fsg_dev *fsg)
 	/* Cancel all the pending transfers */
 	if (fsg->intreq_busy)
 		usb_ep_dequeue(fsg->intr_in, fsg->intreq);
-	for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
+	for (i = 0; i < fsg_num_buffers; ++i) {
 		bh = &fsg->buffhds[i];
 		if (bh->inreq_busy)
 			usb_ep_dequeue(fsg->bulk_in, bh->inreq);
@@ -2913,7 +2899,7 @@ static void handle_exception(struct fsg_dev *fsg)
 	/* Wait until everything is idle */
 	for (;;) {
 		num_active = fsg->intreq_busy;
-		for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
+		for (i = 0; i < fsg_num_buffers; ++i) {
 			bh = &fsg->buffhds[i];
 			num_active += bh->inreq_busy + bh->outreq_busy;
 		}
@@ -2935,7 +2921,7 @@ static void handle_exception(struct fsg_dev *fsg)
 	 * state, and the exception.  Then invoke the handler. */
 	spin_lock_irq(&fsg->lock);
 
-	for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
+	for (i = 0; i < fsg_num_buffers; ++i) {
 		bh = &fsg->buffhds[i];
 		bh->state = BUF_STATE_EMPTY;
 	}
@@ -3165,7 +3151,7 @@ static void /* __init_or_exit */ fsg_unbind(struct usb_gadget *gadget)
 	}
 
 	/* Free the data buffers */
-	for (i = 0; i < FSG_NUM_BUFFERS; ++i)
+	for (i = 0; i < fsg_num_buffers; ++i)
 		kfree(fsg->buffhds[i].buf);
 
 	/* Free the request and buffer for endpoint 0 */
@@ -3453,7 +3439,7 @@ static int __init fsg_bind(struct usb_gadget *gadget)
 	req->complete = ep0_complete;
 
 	/* Allocate the data buffers */
-	for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
+	for (i = 0; i < fsg_num_buffers; ++i) {
 		struct fsg_buffhd	*bh = &fsg->buffhds[i];
 
 		/* Allocate for the bulk-in endpoint.  We assume that
@@ -3464,7 +3450,7 @@ static int __init fsg_bind(struct usb_gadget *gadget)
 			goto out;
 		bh->next = bh + 1;
 	}
-	fsg->buffhds[FSG_NUM_BUFFERS - 1].next = &fsg->buffhds[0];
+	fsg->buffhds[fsg_num_buffers - 1].next = &fsg->buffhds[0];
 
 	/* This should reflect the actual gadget power source */
 	usb_gadget_set_selfpowered(gadget);
@@ -3580,7 +3566,9 @@ static int __init fsg_alloc(void)
 {
 	struct fsg_dev		*fsg;
 
-	fsg = kzalloc(sizeof *fsg, GFP_KERNEL);
+	fsg = kzalloc(sizeof *fsg +
+		      fsg_num_buffers * sizeof *(fsg->buffhds), GFP_KERNEL);
+
 	if (!fsg)
 		return -ENOMEM;
 	spin_lock_init(&fsg->lock);
@@ -3598,6 +3586,10 @@ static int __init fsg_init(void)
 	int		rc;
 	struct fsg_dev	*fsg;
 
+	rc = fsg_num_buffers_validate();
+	if (rc != 0)
+		return rc;
+
 	if ((rc = fsg_alloc()) != 0)
 		return rc;
 	fsg = the_fsg;
diff --git a/drivers/usb/gadget/storage_common.c b/drivers/usb/gadget/storage_common.c
index 571d9730fca..523626274c0 100644
--- a/drivers/usb/gadget/storage_common.c
+++ b/drivers/usb/gadget/storage_common.c
@@ -43,6 +43,12 @@
  * characters rather then a pointer to void.
  */
 
+/*
+ * When USB_GADGET_DEBUG_FILES is defined the module param num_buffers
+ * sets the number of pipeline buffers (length of the fsg_buffhd array).
+ * The valid range of num_buffers is: num >= 2 && num <= 4.
+ */
+
 
 #include <linux/usb/storage.h>
 #include <scsi/scsi.h>
@@ -238,6 +244,8 @@ struct fsg_lun {
 	u32		sense_data_info;
 	u32		unit_attention_data;
 
+	unsigned int	blkbits;	/* Bits of logical block size of bound block device */
+	unsigned int	blksize;	/* logical block size of bound block device */
 	struct device	dev;
 };
 
@@ -253,8 +261,31 @@ static struct fsg_lun *fsg_lun_from_dev(struct device *dev)
 #define EP0_BUFSIZE	256
 #define DELAYED_STATUS	(EP0_BUFSIZE + 999)	/* An impossibly large value */
 
-/* Number of buffers we will use.  2 is enough for double-buffering */
-#define FSG_NUM_BUFFERS	2
+#ifdef CONFIG_USB_GADGET_DEBUG_FILES
+
+static unsigned int fsg_num_buffers = CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS;
+module_param_named(num_buffers, fsg_num_buffers, uint, S_IRUGO);
+MODULE_PARM_DESC(num_buffers, "Number of pipeline buffers");
+
+#else
+
+/*
+ * Number of buffers we will use.
+ * 2 is usually enough for good buffering pipeline
+ */
+#define fsg_num_buffers	CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS
+
+#endif /* CONFIG_USB_DEBUG */
+
+/* check if fsg_num_buffers is within a valid range */
+static inline int fsg_num_buffers_validate(void)
+{
+	if (fsg_num_buffers >= 2 && fsg_num_buffers <= 4)
+		return 0;
+	pr_err("fsg_num_buffers %u is out of range (%d to %d)\n",
+	       fsg_num_buffers, 2 ,4);
+	return -EINVAL;
+}
 
 /* Default size of buffer length. */
 #define FSG_BUFLEN	((u32)16384)
@@ -571,13 +602,24 @@ static int fsg_lun_open(struct fsg_lun *curlun, const char *filename)
 		rc = (int) size;
 		goto out;
 	}
-	num_sectors = size >> 9;	/* File size in 512-byte blocks */
+
+	if (curlun->cdrom) {
+		curlun->blksize = 2048;
+		curlun->blkbits = 11;
+	} else if (inode->i_bdev) {
+		curlun->blksize = bdev_logical_block_size(inode->i_bdev);
+		curlun->blkbits = blksize_bits(curlun->blksize);
+	} else {
+		curlun->blksize = 512;
+		curlun->blkbits = 9;
+	}
+
+	num_sectors = size >> curlun->blkbits; /* File size in logic-block-size blocks */
 	min_sectors = 1;
 	if (curlun->cdrom) {
-		num_sectors &= ~3;	/* Reduce to a multiple of 2048 */
-		min_sectors = 300*4;	/* Smallest track is 300 frames */
-		if (num_sectors >= 256*60*75*4) {
-			num_sectors = (256*60*75 - 1) * 4;
+		min_sectors = 300;	/* Smallest track is 300 frames */
+		if (num_sectors >= 256*60*75) {
+			num_sectors = 256*60*75 - 1;
 			LINFO(curlun, "file too big: %s\n", filename);
 			LINFO(curlun, "using only first %d blocks\n",
 					(int) num_sectors);