From e6456186cae76f80446ba911f77eb2f85d3d927e Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Tue, 25 Feb 2014 11:40:16 +0100 Subject: [PATCH] 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 Signed-off-by: Mark Brown --- drivers/spi/spidev.c | 4 ++-- 1 file 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;