Unverified Commit 84855678 authored May 15, 2020 by Lukas Wunner Committed by Mark Brown May 20, 2020

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 ffbbdd21 ("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: ffbbdd21 ("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>

parent 0392727c

drivers/spi/spi.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -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);

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