Revert "drm/amd/display: edp do not add non-edid timings"

commit d614908 upstream.

This change causes regression when eDP and external display in mirror
mode. When external display supports low resolution than eDP, use eDP
timing to driver external display may cause corruption on external
display.

This reverts commit e749dd1.

Cc: [email protected]
Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2655
Signed-off-by: Hersen Wu <[email protected]>
Reviewed-by: Mario Limonciello <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: Hersen Wu

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -6988,13 +6988,7 @@ static int amdgpu_dm_connector_get_modes(struct drm_connector *connector)
 				drm_add_modes_noedid(connector, 640, 480);
 	} else {
 		amdgpu_dm_connector_ddc_get_modes(connector, edid);
-		/* most eDP supports only timings from its edid,
-		 * usually only detailed timings are available
-		 * from eDP edid. timings which are not from edid
-		 * may damage eDP
-		 */
-		if (connector->connector_type != DRM_MODE_CONNECTOR_eDP)
-			amdgpu_dm_connector_add_common_modes(encoder, connector);
+		amdgpu_dm_connector_add_common_modes(encoder, connector);
 		amdgpu_dm_connector_add_freesync_modes(connector, edid);
 	}
 	amdgpu_dm_fbc_init(connector);