Re: FAILED: patch "[PATCH] platform/chrome: cros_ec_rpmsg: Fix race with host command" failed to apply to 5.3-stable tree

[Sasha Levin <sashal@kernel.org>]

On Thu, Oct 03, 2019 at 02:10:05PM +0200, gregkh@linuxfoundation.org wrote:
>
>The patch below does not apply to the 5.3-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 71cddb7097e2b0feb855d7fd7d59afd12cbee4bb Mon Sep 17 00:00:00 2001
>From: Pi-Hsun Shih <pihsun@chromium.org>
>Date: Wed, 4 Sep 2019 14:26:13 +0800
>Subject: [PATCH] platform/chrome: cros_ec_rpmsg: Fix race with host command
> when probe failed
>
>Since the rpmsg_endpoint is created before probe is called, it's
>possible that a host event is received during cros_ec_register, and
>there would be some pending work in the host_event_work workqueue while
>cros_ec_register is called.
>
>If cros_ec_register fails, when the leftover work in host_event_work
>run, the ec_dev from the drvdata of the rpdev could be already set to
>NULL, causing kernel crash when trying to run cros_ec_get_next_event.
>
>Fix this by creating the rpmsg_endpoint by ourself, and when
>cros_ec_register fails (or on remove), destroy the endpoint first (to
>make sure there's no more new calls to cros_ec_rpmsg_callback), and then
>cancel all works in the host_event_work workqueue.
>
>Cc: stable@vger.kernel.org
>Fixes: 2de89fd98958 ("platform/chrome: cros_ec: Add EC host command support using rpmsg")
>Signed-off-by: Pi-Hsun Shih <pihsun@chromium.org>
>Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

I've worked around the changes introduced by 7aa703bb88243 ("mfd /
platform: cros_ec: Handle chained ECs as platform devices"). Queued for
5.3 and 5.2.

-- 
Thanks,
Sasha