From: Lukas Wunner lukas@wunner.de
commit 84855678add8aba927faf76bc2f130a40f94b6f7 upstream.
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 ffbbdd21329f ("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: ffbbdd21329f ("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.158955752... Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/spi/spi.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -2768,6 +2768,8 @@ void spi_unregister_controller(struct sp 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); @@ -2780,7 +2782,6 @@ void spi_unregister_controller(struct sp 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);