This is a note to let you know that I've just added the patch titled drm/msm/dp: fix panel bridge attachment 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-msm-dp-fix-panel-bridge-attachment.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. commit c7d1fbf1af425951a5a382c6c2a171beab421a64 Author: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> Date: Sat Feb 12 01:40:02 2022 +0300 drm/msm/dp: fix panel bridge attachment [ Upstream commit 4d793a02c4967ab14d4ae5e86a51ee02ed78921a ] In commit 8a3b4c17f863 ("drm/msm/dp: employ bridge mechanism for display enable and disable") the DP driver received a drm_bridge instance, which is always attached to the encoder as a root bridge. However it conflicts with the panel_bridge support for eDP panels. The panel bridge attaches to the encoder before the "dp" bridge (DP driver's drm_bridge instance created in msm_dp_bridge_init()) has a chance to do so. Change panel bridge attachment to come after the "dp" bridge attachment (and to use it as a previous bridge). Fixes: 8a3b4c17f863 ("drm/msm/dp: employ bridge mechanism for display enable and disable") Cc: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> Tested-by: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx> Reviewed-by: Stephen Boyd <swboyd@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/20220211224006.1797846-2-dmitry.baryshkov@xxxxxxxxxx [db: fixed commit message according to Stephen's suggestions] Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/gpu/drm/msm/dp/dp_drm.c b/drivers/gpu/drm/msm/dp/dp_drm.c index d4d360d19eba..26ef41a4c1b6 100644 --- a/drivers/gpu/drm/msm/dp/dp_drm.c +++ b/drivers/gpu/drm/msm/dp/dp_drm.c @@ -169,16 +169,6 @@ struct drm_connector *dp_drm_connector_init(struct msm_dp *dp_display) drm_connector_attach_encoder(connector, dp_display->encoder); - if (dp_display->panel_bridge) { - ret = drm_bridge_attach(dp_display->encoder, - dp_display->panel_bridge, NULL, - DRM_BRIDGE_ATTACH_NO_CONNECTOR); - if (ret < 0) { - DRM_ERROR("failed to attach panel bridge: %d\n", ret); - return ERR_PTR(ret); - } - } - return connector; } @@ -246,5 +236,16 @@ struct drm_bridge *msm_dp_bridge_init(struct msm_dp *dp_display, struct drm_devi return ERR_PTR(rc); } + if (dp_display->panel_bridge) { + rc = drm_bridge_attach(dp_display->encoder, + dp_display->panel_bridge, bridge, + DRM_BRIDGE_ATTACH_NO_CONNECTOR); + if (rc < 0) { + DRM_ERROR("failed to attach panel bridge: %d\n", rc); + drm_bridge_remove(bridge); + return ERR_PTR(rc); + } + } + return bridge; }