This is a note to let you know that I've just added the patch titled drm/msm/dp: always add fail-safe mode into connector mode list to the 5.15-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-msm-dp-always-add-fail-safe-mode-into-connector-.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 4d80b92a4262a648e1158a01b0d234ddc1e7fdb7 Author: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx> Date: Mon Jan 24 15:17:54 2022 -0800 drm/msm/dp: always add fail-safe mode into connector mode list [ Upstream commit d4aca422539c441a7f3fec749287b36de37d9b6b ] Some of DP link compliant test expects to return fail-safe mode if prefer detailed timing mode can not be supported by mainlink's lane and rate after link training. Therefore add fail-safe mode into connector mode list as backup mode. This patch fixes test case 4.2.2.1. Changes in v2: -- add Fixes text string Fixes: 4b85d405cfe9 ( "drm/msm/dp: reduce link rate if failed at link training 1") Signed-off-by: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx> Reviewed-by: Stephen Boyd <swboyd@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/1643066274-25814-1-git-send-email-quic_khsieh@xxxxxxxxxxx Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/gpu/drm/msm/dp/dp_panel.c b/drivers/gpu/drm/msm/dp/dp_panel.c index 2181b60e1d1d..5f23e6f09199 100644 --- a/drivers/gpu/drm/msm/dp/dp_panel.c +++ b/drivers/gpu/drm/msm/dp/dp_panel.c @@ -212,6 +212,11 @@ int dp_panel_read_sink_caps(struct dp_panel *dp_panel, if (drm_add_modes_noedid(connector, 640, 480)) drm_set_preferred_mode(connector, 640, 480); mutex_unlock(&connector->dev->mode_config.mutex); + } else { + /* always add fail-safe mode as backup mode */ + mutex_lock(&connector->dev->mode_config.mutex); + drm_add_modes_noedid(connector, 640, 480); + mutex_unlock(&connector->dev->mode_config.mutex); } if (panel->aux_cfg_update_done) {