This is a note to let you know that I've just added the patch titled
drm/bridge: analogix_dp: Grab runtime PM reference for DP-AUX
to the 5.17-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-bridge-analogix_dp-grab-runtime-pm-reference-for-dp-aux.patch
and it can be found in the queue-5.17 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 8fb6c44fe8468f92ac7b8bbfcca4404a4e88645f Mon Sep 17 00:00:00 2001
From: Brian Norris <briannorris@xxxxxxxxxxxx>
Date: Tue, 1 Mar 2022 18:11:38 -0800
Subject: drm/bridge: analogix_dp: Grab runtime PM reference for DP-AUX
From: Brian Norris <briannorris@xxxxxxxxxxxx>
commit 8fb6c44fe8468f92ac7b8bbfcca4404a4e88645f upstream.
If the display is not enable()d, then we aren't holding a runtime PM
reference here. Thus, it's easy to accidentally cause a hang, if user
space is poking around at /dev/drm_dp_aux0 at the "wrong" time.
Let's get a runtime PM reference, and check that we "see" the panel.
Don't force any panel power-up, etc., because that can be intrusive, and
that's not what other drivers do (see
drivers/gpu/drm/bridge/ti-sn65dsi86.c and
drivers/gpu/drm/bridge/parade-ps8640.c.)
Fixes: 0d97ad03f422 ("drm/bridge: analogix_dp: Remove duplicated code")
Cc: <stable@xxxxxxxxxxxxxxx>
Cc: Tomeu Vizoso <tomeu.vizoso@xxxxxxxxxxxxx>
Signed-off-by: Brian Norris <briannorris@xxxxxxxxxxxx>
Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20220301181107.v4.1.I773a08785666ebb236917b0c8e6c05e3de471e75@changeid
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
@@ -1632,8 +1632,19 @@ static ssize_t analogix_dpaux_transfer(s
struct drm_dp_aux_msg *msg)
{
struct analogix_dp_device *dp = to_dp(aux);
+ int ret;
- return analogix_dp_transfer(dp, msg);
+ pm_runtime_get_sync(dp->dev);
+
+ ret = analogix_dp_detect_hpd(dp);
+ if (ret)
+ goto out;
+
+ ret = analogix_dp_transfer(dp, msg);
+out:
+ pm_runtime_put(dp->dev);
+
+ return ret;
}
struct analogix_dp_device *
Patches currently in stable-queue which might be from briannorris@xxxxxxxxxxxx are
queue-5.17/pm-devfreq-rk3399_dmc-disable-edev-on-remove.patch
queue-5.17/mwifiex-add-mutex-lock-for-call-in-mwifiex_dfs_chan_.patch
queue-5.17/ath10k-skip-ath10k_halt-during-suspend-for-driver-st.patch
queue-5.17/platform-chrome-re-introduce-cros_ec_cmd_xfer-and-us.patch
queue-5.17/drm-bridge-analogix_dp-grab-runtime-pm-reference-for-dp-aux.patch
