Merge pull request torvalds#257 from Radxa-Alvin/linux-5.10-gen-rkr4.1

Changes:
  * drm/bridge: synopsys: dw-hdmi: HDMI prioritize panel preferred resolution

Signed-off-by: Stephen Chen <[email protected]>

Author: RadxaStephen

drivers/gpu/drm/bridge/synopsys/dw-hdmi.c

@@ -3107,6 +3107,7 @@ static int dw_hdmi_connector_get_modes(struct drm_connector *connector)
 	void *data = hdmi->plat_data->phy_data;
 	int i,  ret = 0;
 	struct drm_display_mode *preferred_mode = NULL;
+	struct drm_display_mode *default_mode = NULL;
 
 	memset(metedata, 0, sizeof(*metedata));
 	edid = dw_hdmi_get_edid(hdmi, connector);
@@ -3160,24 +3161,58 @@ static int dw_hdmi_connector_get_modes(struct drm_connector *connector)
 	dw_hdmi_check_output_type_changed(hdmi);
 
 	if ((hdmi->preset_max_hdisplay) && (hdmi->preset_max_vdisplay)) {
+#ifdef DEBUG
+#define MODE_DBG(x)		(dev_err(hdmi->dev, "hdisplay: %d vdisplay: %d flags: %x refresh: %d\n", x->hdisplay, x->vdisplay, x->flags, drm_mode_vrefresh(x)))
+#define MODE_MSG(x)		(dev_err(hdmi->dev, x))
+#else
+#define MODE_DBG(x)		{}
+#define MODE_MSG(x)		{}
+#endif
+#define IS_PREFERRED(x) (x->flags & DRM_MODE_TYPE_PREFERRED)
+#define PIXEL_COUNT(x)  (x->hdisplay * x->vdisplay)
+#define IS_BETTER(x, y) ((PIXEL_COUNT(x) <= hdmi->preset_max_hdisplay * hdmi->preset_max_vdisplay && !(x->flags & DRM_MODE_FLAG_INTERLACE) && drm_mode_vrefresh(x) <= 60) && \
+			 (PIXEL_COUNT(x) > PIXEL_COUNT(y) || (PIXEL_COUNT(x) == PIXEL_COUNT(y) && drm_mode_vrefresh(x) >= drm_mode_vrefresh(y)) || PIXEL_COUNT(y) > hdmi->preset_max_hdisplay * hdmi->preset_max_vdisplay || drm_mode_vrefresh(y) > 60))
+
+		// Find default mode
 		list_for_each_entry(mode, &connector->probed_modes, head) {
-			mode->type &= ~DRM_MODE_TYPE_PREFERRED;
-			if (mode->hdisplay == hdmi->preset_max_hdisplay &&
-				mode->vdisplay == hdmi->preset_max_vdisplay) {
-				preferred_mode?:(preferred_mode = mode);
-				if(!(mode->flags & DRM_MODE_FLAG_INTERLACE)) {
-					if((preferred_mode->flags & DRM_MODE_FLAG_INTERLACE) || (
-					   drm_mode_vrefresh(mode) >
-					   drm_mode_vrefresh(preferred_mode) &&
-					   drm_mode_vrefresh(mode) <= 60)) {
-						preferred_mode = mode;
-					}
-				}
+			if (IS_PREFERRED(mode)) {
+				default_mode = mode;
+				MODE_MSG("found default_mode\n");
+				MODE_DBG(default_mode);
+				break;
 			}
 		}
 
-		if (preferred_mode)
+		// Provide a sane initial mode for later comparision
+		if (default_mode) {
+			preferred_mode = default_mode;
+			MODE_MSG("preferred_mode = default_mode\n");
+		}
+		else {
+			preferred_mode = list_entry(&connector->probed_modes, struct drm_display_mode, head);
+			MODE_MSG("preferred_mode = connector->probed_modes[0]\n");
+			MODE_DBG(preferred_mode);
+		}
+
+		// Searching for better mode within our criteria
+		list_for_each_entry(mode, &connector->probed_modes, head) {
+			if (IS_BETTER(mode, preferred_mode)) {
+				preferred_mode = mode;
+				MODE_MSG("preferred_mode updated\n");
+				MODE_DBG(preferred_mode);
+			}
+		}
+
+		// Update preferred mode
+		if (!default_mode) {
 			preferred_mode->type |= DRM_MODE_TYPE_PREFERRED;
+			MODE_MSG("missing default_mode, preferred_mode used as default_mode\n");
+		}
+		else if (PIXEL_COUNT(default_mode) > hdmi->preset_max_hdisplay * hdmi->preset_max_vdisplay) {
+			default_mode->type &= ~DRM_MODE_TYPE_PREFERRED;
+			preferred_mode->type |= DRM_MODE_TYPE_PREFERRED;
+			MODE_MSG("default_mode resolution is above limit\n");
+		}
 	}
 
 	return ret;