From c15f6ed3a18f10cdc33f64906ab353f17a6df114 Mon Sep 17 00:00:00 2001 From: Nicolas Boichat Date: Mon, 17 Aug 2015 11:52:54 +0800 Subject: 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 Signed-off-by: Mark Brown --- drivers/spi/spi-bitbang.c | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-) (limited to 'drivers/spi/spi-bitbang.c') 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; -- cgit v1.2.3