On Thu, Oct 03, 2019 at 02:10:05PM +0200, gregkh@xxxxxxxxxxxxxxxxxxx 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@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 71cddb7097e2b0feb855d7fd7d59afd12cbee4bb Mon Sep 17 00:00:00 2001
From: Pi-Hsun Shih <pihsun@xxxxxxxxxxxx>
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@xxxxxxxxxxxxxxx
Fixes: 2de89fd98958 ("platform/chrome: cros_ec: Add EC host command support using rpmsg")
Signed-off-by: Pi-Hsun Shih <pihsun@xxxxxxxxxxxx>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>
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
