drm/edid: Use GTF2 for inferred modes

For some reason we only use the secondary GTF curve for the
standard timings. Use it for inferred modes as well.
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220927170006.27855-6-ville.syrjala@linux.intel.com

drivers/gpu/drm/drm_edid.c

@@ -3546,6 +3546,35 @@ static int drm_gtf_modes_for_range(struct drm_connector *connector,
 	return modes;
 }
 
+static int drm_gtf2_modes_for_range(struct drm_connector *connector,
+				    const struct drm_edid *drm_edid,
+				    const struct detailed_timing *timing)
+{
+	int i, modes = 0;
+	struct drm_display_mode *newmode;
+	struct drm_device *dev = connector->dev;
+
+	for (i = 0; i < ARRAY_SIZE(extra_modes); i++) {
+		const struct minimode *m = &extra_modes[i];
+
+		newmode = drm_gtf2_mode(dev, drm_edid, m->w, m->h, m->r);
+		if (!newmode)
+			return modes;
+
+		drm_mode_fixup_1366x768(newmode);
+		if (!mode_in_range(newmode, drm_edid, timing) ||
+		    !valid_inferred_mode(connector, newmode)) {
+			drm_mode_destroy(dev, newmode);
+			continue;
+		}
+
+		drm_mode_probed_add(connector, newmode);
+		modes++;
+	}
+
+	return modes;
+}
+
 static int drm_cvt_modes_for_range(struct drm_connector *connector,
 				   const struct drm_edid *drm_edid,
 				   const struct detailed_timing *timing)
@@ -3594,7 +3623,11 @@ do_inferred_modes(const struct detailed_timing *timing, void *c)
 		return; /* GTF not defined yet */
 
 	switch (range->flags) {
-	case DRM_EDID_SECONDARY_GTF_SUPPORT_FLAG: /* XXX could do more */
+	case DRM_EDID_SECONDARY_GTF_SUPPORT_FLAG:
+		closure->modes += drm_gtf2_modes_for_range(closure->connector,
+							   closure->drm_edid,
+							   timing);
+		break;
 	case DRM_EDID_DEFAULT_GTF_SUPPORT_FLAG:
 		closure->modes += drm_gtf_modes_for_range(closure->connector,
 							  closure->drm_edid,