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spi: Fix controller unregister order 

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>
alistair/sunxi64-5.8
Lukas Wunner 2020-05-15 17:58:01 +02:00 committed by Mark Brown
parent 0392727c26
commit 84855678ad
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GPG Key ID: 24D68B725D5487D0
1 changed files with 2 additions and 1 deletions
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3
drivers/spi/spi.c
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@ -2763,6 +2763,8 @@ 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);
@ -2775,7 +2777,6 @@ 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);