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spi: fix possible deadlock between internal bus locks and bus_lock_flag

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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: 49023d2e4e ("spi: core: Fix deadlock when sending messages")
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Heiko Stübner 2016-03-18 11:15:11 +01:00 committed by Mark Brown
parent c508709bcf
commit 24c8cd1b08
1 changed files with 2 additions and 2 deletions
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4
drivers/spi/spi.c
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@ -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);