Commit 4d793a02 authored Feb 12, 2022 by Dmitry Baryshkov

drm/msm/dp: fix panel bridge attachment



In commit 8a3b4c17 ("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: 8a3b4c17 ("drm/msm/dp: employ bridge mechanism for display enable and disable")
Cc: Kuogee Hsieh <quic_khsieh@quicinc.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Tested-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20220211224006.1797846-2-dmitry.baryshkov@linaro.org


[db: fixed commit message according to Stephen's suggestions]
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

parent 2af0fc92

drivers/gpu/drm/msm/dp/dp_drm.c

+11 −10

Original line number	Diff line number	Diff line
		@@ -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;
		}