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authorGeert Uytterhoeven <geert+renesas@linux-m68k.org>2014-02-25 11:40:16 +0100
committerMark Brown <broonie@linaro.org>2014-02-27 05:50:33 +0100
commite6456186cae76f80446ba911f77eb2f85d3d927e (patch)
tree0dc81d3d47f8c7e7611c3fdb66068cd6ee8d6944
parentspi/spidev_test: Document -N/--no-cs and -R/--ready (diff)
downloadlinux-e6456186cae76f80446ba911f77eb2f85d3d927e.tar.xz
linux-e6456186cae76f80446ba911f77eb2f85d3d927e.zip
spi: spidev: Restore all SPI mode flags on ioctl failure
In commit f477b7fb13df2b843997559ff34e87d054ba6538 ("spi: DUAL and QUAD support"), spi_device.mode was enlarged from 8 to 16 bits. However, the spidev code still only saved 8 bits of data. If a spidev SPI_IOC_WR_MODE or SPI_IOC_WR_LSB_FIRST request failed, only the lower 8 bits of the SPI mode were restored, inadvertently clearing the upper 8 bits, possibly disabling Quad or Dual SPI transfers for the device. Save up to 32 bits to fix this. For SPI_IOC_WR_MODE this is probably not so important, as it doesn't allow setting Quad or Dual mode anyway, but SPI_IOC_WR_LSB_FIRST is used to just set or clear a single bit. Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Signed-off-by: Mark Brown <broonie@linaro.org>
-rw-r--r--drivers/spi/spidev.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c
index d7c6e36021e8..2abc0f5a82be 100644
--- a/drivers/spi/spidev.c
+++ b/drivers/spi/spidev.c
@@ -374,7 +374,7 @@ spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
case SPI_IOC_WR_MODE:
retval = __get_user(tmp, (u8 __user *)arg);
if (retval == 0) {
- u8 save = spi->mode;
+ u32 save = spi->mode;
if (tmp & ~SPI_MODE_MASK) {
retval = -EINVAL;
@@ -393,7 +393,7 @@ spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
case SPI_IOC_WR_LSB_FIRST:
retval = __get_user(tmp, (__u8 __user *)arg);
if (retval == 0) {
- u8 save = spi->mode;
+ u32 save = spi->mode;
if (tmp)
spi->mode |= SPI_LSB_FIRST;