From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@linux.intel.com>
Date: Tue, 8 May 2018 16:39:39 +0530
Subject: drm/edid: Don't send bogus aspect ratios in AVI infoframes
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Git-commit: a9c266c27ee568e3028b804a447b1fea58209618
Patch-mainline: v4.18-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

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@intel.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Jose Abreu <Jose.Abreu@synopsys.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Shashank Sharma <shashank.sharma@intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1525777785-9740-5-git-send-email-ankit.k.nautiyal@intel.com

Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/drm_edid.c |   23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -4833,6 +4833,7 @@ drm_hdmi_avi_infoframe_from_display_mode
 					 const struct drm_display_mode *mode,
 					 bool is_hdmi2_sink)
 {
+	enum hdmi_picture_aspect picture_aspect;
 	int err;
 
 	if (!frame || !mode)
@@ -4875,13 +4876,23 @@ drm_hdmi_avi_infoframe_from_display_mode
 	 * 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;