diff options
| author | Nicolas Boichat <drinkcat@chromium.org> | 2015-08-17 06:52:54 +0300 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2015-09-17 14:13:40 +0300 |
| commit | c15f6ed3a18f10cdc33f64906ab353f17a6df114 (patch) | |
| tree | d31632b7d325d16e602437062832c01eabae2451 /drivers/spi/spi-bitbang.c | |
| parent | 6ff33f3902c3b1c5d0db6b1e2c70b6d76fba357f (diff) | |
| download | linux-c15f6ed3a18f10cdc33f64906ab353f17a6df114.tar.xz | |
spi: bitbang: Replace spinlock by mutex
chipselect (in the case of spi-gpio: spi_gpio_chipselect, which
calls gpiod_set_raw_value_cansleep) can sleep, so we should not
hold a spinlock while calling it from spi_bitbang_setup.
This issue was introduced by this commit, which converted spi-gpio
to cansleep variants:
d9dda5a191 "spi: spi-gpio: Use 'cansleep' variants to access GPIO"
Replacing the lock variable by a mutex fixes the issue: This is
safe as all instances where the lock is used are called from
contexts that can sleep.
Finally, update spi-ppc4xx and and spi-s3c24xx to use mutex
functions, as they directly hold the lock for similar purpose.
Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi/spi-bitbang.c')
| -rw-r--r-- | drivers/spi/spi-bitbang.c | 17 |
1 files changed, 7 insertions, 10 deletions
diff --git a/drivers/spi/spi-bitbang.c b/drivers/spi/spi-bitbang.c index 840a4984d365..ef43ef507c9a 100644 --- a/drivers/spi/spi-bitbang.c +++ b/drivers/spi/spi-bitbang.c @@ -180,7 +180,6 @@ int spi_bitbang_setup(struct spi_device *spi) { struct spi_bitbang_cs *cs = spi->controller_state; struct spi_bitbang *bitbang; - unsigned long flags; bitbang = spi_master_get_devdata(spi->master); @@ -210,12 +209,12 @@ int spi_bitbang_setup(struct spi_device *spi) */ /* deselect chip (low or high) */ - spin_lock_irqsave(&bitbang->lock, flags); + mutex_lock(&bitbang->lock); if (!bitbang->busy) { bitbang->chipselect(spi, BITBANG_CS_INACTIVE); ndelay(cs->nsecs); } - spin_unlock_irqrestore(&bitbang->lock, flags); + mutex_unlock(&bitbang->lock); return 0; } @@ -255,13 +254,12 @@ static int spi_bitbang_bufs(struct spi_device *spi, struct spi_transfer *t) static int spi_bitbang_prepare_hardware(struct spi_master *spi) { struct spi_bitbang *bitbang; - unsigned long flags; bitbang = spi_master_get_devdata(spi); - spin_lock_irqsave(&bitbang->lock, flags); + mutex_lock(&bitbang->lock); bitbang->busy = 1; - spin_unlock_irqrestore(&bitbang->lock, flags); + mutex_unlock(&bitbang->lock); return 0; } @@ -378,13 +376,12 @@ static int spi_bitbang_transfer_one(struct spi_master *master, static int spi_bitbang_unprepare_hardware(struct spi_master *spi) { struct spi_bitbang *bitbang; - unsigned long flags; bitbang = spi_master_get_devdata(spi); - spin_lock_irqsave(&bitbang->lock, flags); + mutex_lock(&bitbang->lock); bitbang->busy = 0; - spin_unlock_irqrestore(&bitbang->lock, flags); + mutex_unlock(&bitbang->lock); return 0; } @@ -427,7 +424,7 @@ int spi_bitbang_start(struct spi_bitbang *bitbang) if (!master || !bitbang->chipselect) return -EINVAL; - spin_lock_init(&bitbang->lock); + mutex_init(&bitbang->lock); if (!master->mode_bits) master->mode_bits = SPI_CPOL | SPI_CPHA | bitbang->flags; |