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authorTrent Piepho <tpiepho@gmail.com>2013-10-01 13:15:25 -0700
committerMark Brown <broonie@linaro.org>2013-10-18 01:00:31 +0100
commit9c97e3421fa0aeec131689008181f8ee1dac5e99 (patch)
tree365c0f4bce04f8c6b26099521256e3cfa07e8c00 /drivers/spi
parent1a33073fcf11e70447b704c0228e28099e6ab39d (diff)
downloadlinux-9c97e3421fa0aeec131689008181f8ee1dac5e99.tar.bz2
spi: spi-mxs: Fix race in setup method
Despite many warnings in the SPI documentation and code, the spi-mxs driver sets shared chip registers in the ->setup method. This method can be called when transfers are in progress on other slaves controlled by the master. Setting registers or any other shared state will corrupt those transfers. So fix mxs_spi_setup() to not call mxs_spi_setup_transfer(). mxs_spi_setup_transfer() is already called for each transfer when they are actually performed in mxs_spi_transfer_one(), so the call in mxs_spi_setup() isn't necessary to setup anything. Signed-off-by: Trent Piepho <tpiepho@gmail.com> Cc: Marek Vasut <marex@denx.de> Cc: Fabio Estevam <fabio.estevam@freescale.com> Cc: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Mark Brown <broonie@linaro.org>
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/spi-mxs.c10
1 files changed, 1 insertions, 9 deletions
diff --git a/drivers/spi/spi-mxs.c b/drivers/spi/spi-mxs.c
index 8cb5d8b6f042..e9cbdb6b1309 100644
--- a/drivers/spi/spi-mxs.c
+++ b/drivers/spi/spi-mxs.c
@@ -103,21 +103,13 @@ static int mxs_spi_setup_transfer(struct spi_device *dev,
static int mxs_spi_setup(struct spi_device *dev)
{
- int err = 0;
-
if (!dev->bits_per_word)
dev->bits_per_word = 8;
if (dev->mode & ~(SPI_CPOL | SPI_CPHA))
return -EINVAL;
- err = mxs_spi_setup_transfer(dev, NULL);
- if (err) {
- dev_err(&dev->dev,
- "Failed to setup transfer, error = %d\n", err);
- }
-
- return err;
+ return 0;
}
static uint32_t mxs_spi_cs_to_reg(unsigned cs)