Re: FAILED: patch "[PATCH] spi: Fix controller unregister order" failed to apply to 4.19-stable tree

[Sasha Levin <sashal@kernel.org>]

On Mon, Jun 15, 2020 at 05:20:44PM +0200, gregkh@linuxfoundation.org wrote:
>
>The patch below does not apply to the 4.19-stable tree.
>If someone wants it applied there, or to any other stable or longterm
>tree, then please email the backport, including the original git commit
>id to <stable@vger.kernel.org>.
>
>thanks,
>
>greg k-h
>
>------------------ original commit in Linus's tree ------------------
>
>From 84855678add8aba927faf76bc2f130a40f94b6f7 Mon Sep 17 00:00:00 2001
>From: Lukas Wunner <lukas@wunner.de>
>Date: Fri, 15 May 2020 17:58:01 +0200
>Subject: [PATCH] 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 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.1589557526.git.lukas@wunner.de
>Signed-off-by: Mark Brown <broonie@kernel.org>

I've also grabbed:

ebc37af5e0a1 ("spi: No need to assign dummy value in spi_unregister_controller()")

And again worked around not having:

8caab75fd2c2 ("spi: Generalize SPI "master" to "controller"")

And queued these two patches for 4.19, 4.14, 4.9, and 4.4.

-- 
Thanks,
Sasha