Merge commit 'v2.6.28-rc2' into x86/pci-ioapic-boot-irq-quirks

1 files changed, 15 insertions, 9 deletions

diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c
index ddbe1a5e970..89a43755a45 100644
--- a/drivers/spi/spidev.c
+++ b/drivers/spi/spidev.c
@@ -228,7 +228,6 @@ static int spidev_message(struct spidev_data *spidev,
 	 * We walk the array of user-provided transfers, using each one
 	 * to initialize a kernel version of the same transfer.
 	 */
-	mutex_lock(&spidev->buf_lock);
 	buf = spidev->buffer;
 	total = 0;
 	for (n = n_xfers, k_tmp = k_xfers, u_tmp = u_xfers;
@@ -296,14 +295,12 @@ static int spidev_message(struct spidev_data *spidev,
 	status = total;
 
 done:
-	mutex_unlock(&spidev->buf_lock);
 	kfree(k_xfers);
 	return status;
 }
 
-static int
-spidev_ioctl(struct inode *inode, struct file *filp,
-		unsigned int cmd, unsigned long arg)
+static long
+spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
 	int			err = 0;
 	int			retval = 0;
@@ -341,6 +338,14 @@ spidev_ioctl(struct inode *inode, struct file *filp,
 	if (spi == NULL)
 		return -ESHUTDOWN;
 
+	/* use the buffer lock here for triple duty:
+	 *  - prevent I/O (from us) so calling spi_setup() is safe;
+	 *  - prevent concurrent SPI_IOC_WR_* from morphing
+	 *    data fields while SPI_IOC_RD_* reads them;
+	 *  - SPI_IOC_MESSAGE needs the buffer locked "normally".
+	 */
+	mutex_lock(&spidev->buf_lock);
+
 	switch (cmd) {
 	/* read requests */
 	case SPI_IOC_RD_MODE:
@@ -456,6 +461,8 @@ spidev_ioctl(struct inode *inode, struct file *filp,
 		kfree(ioc);
 		break;
 	}
+
+	mutex_unlock(&spidev->buf_lock);
 	spi_dev_put(spi);
 	return retval;
 }
@@ -533,7 +540,7 @@ static struct file_operations spidev_fops = {
 	 */
 	.write =	spidev_write,
 	.read =		spidev_read,
-	.ioctl =	spidev_ioctl,
+	.unlocked_ioctl = spidev_ioctl,
 	.open =		spidev_open,
 	.release =	spidev_release,
 };
@@ -577,8 +584,8 @@ static int spidev_probe(struct spi_device *spi)
 
 		spidev->devt = MKDEV(SPIDEV_MAJOR, minor);
 		dev = device_create(spidev_class, &spi->dev, spidev->devt,
-				"spidev%d.%d",
-				spi->master->bus_num, spi->chip_select);
+				    spidev, "spidev%d.%d",
+				    spi->master->bus_num, spi->chip_select);
 		status = IS_ERR(dev) ? PTR_ERR(dev) : 0;
 	} else {
 		dev_dbg(&spi->dev, "no minor number available!\n");
@@ -586,7 +593,6 @@ static int spidev_probe(struct spi_device *spi)
 	}
 	if (status == 0) {
 		set_bit(minor, minors);
-		spi_set_drvdata(spi, spidev);
 		list_add(&spidev->device_entry, &device_list);
 	}
 	mutex_unlock(&device_list_lock);