From mboxrd@z Thu Jan 1 00:00:00 1970 From: Heiko =?ISO-8859-1?Q?St=FCbner?= Subject: [PATCH] spi: don't lock the bus in __spi_pump_messages if it is already locked Date: Fri, 18 Mar 2016 00:18:19 +0100 Message-ID: <1848110.TJtF6nar8z@diego> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: Sender: linux-spi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Mark Brown Cc: Kevin Hilman , Vignesh R , Jon Hunter , linux-rockchip-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-rockchip.vger.kernel.org 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. Fixes: 49023d2e4ead ("spi: core: Fix deadlock when sending messages") Signed-off-by: Heiko Stuebner --- drivers/spi/spi.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index de2f2f9..62f962b 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1160,7 +1160,7 @@ static void __spi_pump_messages(struct spi_master *master, bool in_kthread, } } - if (!bus_locked) + if (!bus_locked && !master->bus_lock_flag) mutex_lock(&master->bus_lock_mutex); trace_spi_message_start(master->cur_msg); @@ -1192,7 +1192,7 @@ static void __spi_pump_messages(struct spi_master *master, bool in_kthread, } out: - if (!bus_locked) + if (!bus_locked && !master->bus_lock_flag) mutex_unlock(&master->bus_lock_mutex); /* Prod the scheduler in case transfer_one() was busy waiting */ -- 2.6.4 -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html