[PATCH 07/10] drm/edid: Don't send bogus aspect ratios in AVI infoframes

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

If the user mode would specify an aspect ratio other than 4:3 or 16:9
we now silently ignore it. Maybe a better apporoach is to return an
error? Let's try that.

Also we must be careful that we don't try to send illegal picture
aspect in the infoframe as it's only capable of signalling none,
4:3, and 16:9. Currently we're sending these bogus infoframes
whenever the cea mode specifies some other aspect ratio.

Cc: Shashank Sharma <shashank.sharma at intel.com>
Cc: Sean Paul <seanpaul at chromium.org>
Cc: Jose Abreu <Jose.Abreu at synopsys.com>
Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
Cc: Emil Velikov <emil.l.velikov at gmail.com>
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/drm_edid.c | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 00aa98f3e55d..bafb3ee4ea97 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -4786,6 +4786,7 @@ drm_hdmi_avi_infoframe_from_display_mode(struct hdmi_avi_infoframe *frame,
 					 const struct drm_display_mode *mode,
 					 bool is_hdmi2_sink)
 {
+	enum hdmi_picture_aspect picture_aspect;
 	int err;
 
 	if (!frame || !mode)
@@ -4828,13 +4829,23 @@ drm_hdmi_avi_infoframe_from_display_mode(struct hdmi_avi_infoframe *frame,
 	 * Populate picture aspect ratio from either
 	 * user input (if specified) or from the CEA mode list.
 	 */
-	if (mode->picture_aspect_ratio == HDMI_PICTURE_ASPECT_4_3 ||
-		mode->picture_aspect_ratio == HDMI_PICTURE_ASPECT_16_9)
-		frame->picture_aspect = mode->picture_aspect_ratio;
-	else if (frame->video_code > 0)
-		frame->picture_aspect = drm_get_cea_aspect_ratio(
-						frame->video_code);
+	picture_aspect = mode->picture_aspect_ratio;
+	if (picture_aspect == HDMI_PICTURE_ASPECT_NONE)
+		picture_aspect = drm_get_cea_aspect_ratio(frame->video_code);
 
+	/*
+	 * The infoframe can't convey anything but none, 4:3
+	 * and 16:9, so if the user has asked for anything else
+	 * we can only satisfy it by specifying the right VIC.
+	 */
+	if (picture_aspect > HDMI_PICTURE_ASPECT_16_9) {
+		if (picture_aspect !=
+		    drm_get_cea_aspect_ratio(frame->video_code))
+			return -EINVAL;
+		picture_aspect = HDMI_PICTURE_ASPECT_NONE;
+	}
+
+	frame->picture_aspect = picture_aspect;
 	frame->active_aspect = HDMI_ACTIVE_ASPECT_PICTURE;
 	frame->scan_mode = HDMI_SCAN_MODE_UNDERSCAN;
 
-- 
2.13.6