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: stable@vger.kernel.org
Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2655
Signed-off-by: Hersen Wu <hersenxs.wu@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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);