diff options
| -rw-r--r-- | drivers/gpu/drm/drm_probe_helper.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c index 425f56280d51..75a71649b64d 100644 --- a/drivers/gpu/drm/drm_probe_helper.c +++ b/drivers/gpu/drm/drm_probe_helper.c @@ -569,8 +569,17 @@ retry: count = drm_add_override_edid_modes(connector); if (count == 0 && (connector->status == connector_status_connected || - connector->status == connector_status_unknown)) + connector->status == connector_status_unknown)) { count = drm_add_modes_noedid(connector, 1024, 768); + + /* + * Section 4.2.2.6 (EDID Corruption Detection) of the DP 1.4a + * Link CTS specifies that 640x480 (the official "failsafe" + * mode) needs to be the default if there's no EDID. + */ + if (connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort) + drm_set_preferred_mode(connector, 640, 480); + } count += drm_helper_probe_add_cmdline_mode(connector); if (count != 0) { ret = __drm_helper_update_and_validate(connector, maxX, maxY, &ctx); |