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authorHeiko Stübner <heiko@sntech.de>2016-04-04 01:20:42 +0000
committerRich Felker <dalias@libc.org>2016-04-07 14:57:31 +0000
commit863c9170406aa56e95612840d8ef1fac0cb56c78 (patch)
treef41ac84b6f0e19a0d952d1e83a7e410897ec65de
parentbaeab9654dcfe9f8e83adf469efc274511c41d61 (diff)
downloadlinux-sh-863c9170406aa56e95612840d8ef1fac0cb56c78.tar.gz
spi: fix possible deadlock between internal bus locks and bus_lock_flag
External users may use spi_bus_lock to get exclusive access. This will also grab the bus_lock_mutex and may therefore result in a deadlock if __spi_pump_messages also tries to get the mutex. Therefore adapt spi_pump_messages as well as spi_sync to preset the bus_locked parameter according to the master->bus_lock_flag. Fixes: 49023d2e4ead ("spi: core: Fix deadlock when sending messages") Signed-off-by: Heiko Stuebner <heiko@sntech.de> Signed-off-by: Mark Brown <broonie@kernel.org>
-rw-r--r--drivers/spi/spi.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index de2f2f90d799..0239b45eed92 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1209,7 +1209,7 @@ static void spi_pump_messages(struct kthread_work *work)
struct spi_master *master =
container_of(work, struct spi_master, pump_messages);
- __spi_pump_messages(master, true, false);
+ __spi_pump_messages(master, true, master->bus_lock_flag);
}
static int spi_init_queue(struct spi_master *master)
@@ -2853,7 +2853,7 @@ static int __spi_sync(struct spi_device *spi, struct spi_message *message,
*/
int spi_sync(struct spi_device *spi, struct spi_message *message)
{
- return __spi_sync(spi, message, 0);
+ return __spi_sync(spi, message, spi->master->bus_lock_flag);
}
EXPORT_SYMBOL_GPL(spi_sync);