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authorAlan Cox <alan@lxorguk.ukuu.org.uk>2008-07-23 21:29:55 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-24 10:47:30 -0700
commit4ef754b7d7971a704d5b1b4608839da1bae37e5e (patch)
treea9db20a2b6ca332653e5d1503fc8d3398b145aa6 /drivers/spi/spidev.c
parent102eb97564c73ea73645b38599c5cbe6f54b030c (diff)
downloadlinux-linaro-stable-4ef754b7d7971a704d5b1b4608839da1bae37e5e.tar.gz
spidev: BKL removal
Another step to removing ->ioctl and to removing the BKL [dbrownell@users.sourceforge.net: take final step; BKL not needed] Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/spi/spidev.c')
-rw-r--r--drivers/spi/spidev.c19
1 files changed, 13 insertions, 6 deletions
diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c
index 2833fd772a24..e5e0cfed5e3b 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,
};