[PATCH 09/15] UBUNTU: SAUCE: drm/i915/edp: always add fixed mode to probed modes in ->get_modes()

[Aaron Ma]

From: Jani Nikula <jani.nikula at intel.com>

BugLink: https://bugs.launchpad.net/bugs/1921318

Unconditionally add fixed mode to probed modes even if EDID is present
and has modes. Prepare for cases where the fixed mode is not present in
EDID (such as eDP MSO).

Cc: Nischal Varide <nischal.varide at intel.com>
Reviewed-by: Uma Shankar <uma.shankar at intel.com>
Signed-off-by: Jani Nikula <jani.nikula at intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/6979f123f3e4ed948333f1b181202bbced3c3e85.1613054234.git.jani.nikula@intel.com
(backported from commit f886261735fca91e3bdec0e56c86a5e71e4eea67
https://anongit.freedesktop.org/git/drm-intel.git drm-intel-next)
Signed-off-by: Aaron Ma <aaron.ma at canonical.com>
---
 drivers/gpu/drm/i915/display/intel_dp.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 7bd374c926b7..40b804230df6 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -6687,15 +6687,14 @@ static int intel_dp_get_modes(struct drm_connector *connector)
 {
 	struct intel_connector *intel_connector = to_intel_connector(connector);
 	struct edid *edid;
+	int num_modes = 0;
 
 	edid = intel_connector->detect_edid;
 	if (edid) {
-		int ret = intel_connector_update_modes(connector, edid);
-		if (ret)
-			return ret;
+		num_modes = intel_connector_update_modes(connector, edid);
 	}
 
-	/* if eDP has no EDID, fall back to fixed mode */
+	/* Also add fixed mode, which may or may not be present in EDID */
 	if (intel_dp_is_edp(intel_attached_dp(intel_connector)) &&
 	    intel_connector->panel.fixed_mode) {
 		struct drm_display_mode *mode;
@@ -6704,10 +6703,13 @@ static int intel_dp_get_modes(struct drm_connector *connector)
 					  intel_connector->panel.fixed_mode);
 		if (mode) {
 			drm_mode_probed_add(connector, mode);
-			return 1;
+			num_modes++;
 		}
 	}
 
+	if (num_modes)
+		return num_modes;
+
 	if (!edid) {
 		struct intel_dp *intel_dp = intel_attached_dp(intel_connector);
 		struct drm_display_mode *mode;
@@ -6717,11 +6719,11 @@ static int intel_dp_get_modes(struct drm_connector *connector)
 					      intel_dp->downstream_ports);
 		if (mode) {
 			drm_mode_probed_add(connector, mode);
-			return 1;
+			num_modes++;
 		}
 	}
 
-	return 0;
+	return num_modes;
 }
 
 static int
-- 
2.25.1