spi: Fix controller unregister order

[ Upstream commit 84855678ad ]

When an SPI controller unregisters, it unbinds all its slave devices.
For this, their drivers may need to access the SPI bus, e.g. to quiesce
interrupts.

However since commit ffbbdd2132 ("spi: create a message queueing
infrastructure"), spi_destroy_queue() is executed before unbinding the
slaves.  It sets ctlr->running = false, thereby preventing SPI bus
access and causing unbinding of slave devices to fail.

Fix by unbinding slaves before calling spi_destroy_queue().

Fixes: ffbbdd2132 ("spi: create a message queueing infrastructure")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: stable@vger.kernel.org # v3.4+
Cc: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/8aaf9d44c153fe233b17bc2dec4eb679898d7e7b.1589557526.git.lukas@wunner.de
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Lukas Wunner
2020-05-15 17:58:01 +02:00
committed by Greg Kroah-Hartman
parent 03a3812928
commit 675efd2778

View File

@@ -2306,6 +2306,8 @@ void spi_unregister_controller(struct spi_controller *ctlr)
struct spi_controller *found;
int id = ctlr->bus_num;
device_for_each_child(&ctlr->dev, NULL, __unregister);
/* First make sure that this controller was ever added */
mutex_lock(&board_lock);
found = idr_find(&spi_master_idr, id);
@@ -2318,7 +2320,6 @@ void spi_unregister_controller(struct spi_controller *ctlr)
list_del(&ctlr->list);
mutex_unlock(&board_lock);
device_for_each_child(&ctlr->dev, NULL, __unregister);
device_unregister(&ctlr->dev);
/* free bus id */
mutex_lock(&board_lock);