[PATCH v6 8/9] drm: Add aspect ratio parsing in DRM layer

[Nautiyal, Ankit K]

From: "Sharma, Shashank" <shashank.sharma at intel.com>

Current DRM layer functions don't parse aspect ratio information
while converting a user mode->kernel mode or vice versa. This
causes modeset to pick mode with wrong aspect ratio, eventually
causing failures in HDMI compliance test cases, due to wrong VIC.

This patch adds aspect ratio information in DRM's mode conversion
and mode comparision functions, to make sure kernel picks mode
with right aspect ratio (as per the VIC).

Background:
This patch was once reviewed and merged, and later reverted due to
lack of DRM cap protection. This is a re-spin of this patch, this
time with DRM cap protection, to avoid aspect ratio information, when
the client doesn't request for it.

Review link: https://pw-emeril.freedesktop.org/patch/104068/
Background discussion: https://patchwork.kernel.org/patch/9379057/

Signed-off-by: Shashank Sharma <shashank.sharma at intel.com>
Signed-off-by: Lin, Jia <lin.a.jia at intel.com>
Signed-off-by: Akashdeep Sharma <akashdeep.sharma at intel.com>
Reviewed-by: Jim Bride <jim.bride at linux.intel.com> (V2)
Reviewed-by: Jose Abreu <Jose.Abreu at synopsys.com> (V4)

Cc: Ville Syrjala <ville.syrjala at linux.intel.com>
Cc: Jim Bride <jim.bride at linux.intel.com>
Cc: Jose Abreu <Jose.Abreu at synopsys.com>
Cc: Ankit Nautiyal <ankit.k.nautiyal at intel.com>

V3: modified the aspect-ratio check in drm_mode_equal as per new flags
    provided by Ville. https://patchwork.freedesktop.org/patch/188043/
V4: rebase
V5: rebase
V6: As recommended by Ville, avoided matching of aspect-ratio in
    drm_fb_helper, while trying to find a common mode among connectors
    for the target clone mode.
---
 drivers/gpu/drm/drm_fb_helper.c | 12 ++++++++++--
 drivers/gpu/drm/drm_modes.c     | 35 ++++++++++++++++++++++++++++++++++-
 2 files changed, 44 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 035784d..8fa4e78 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -2183,7 +2183,11 @@ static bool drm_target_cloned(struct drm_fb_helper *fb_helper,
 		for (j = 0; j < i; j++) {
 			if (!enabled[j])
 				continue;
-			if (!drm_mode_equal(modes[j], modes[i]))
+			if (!drm_mode_match(modes[j], modes[i],
+					    DRM_MODE_MATCH_TIMINGS |
+					    DRM_MODE_MATCH_CLOCK |
+					    DRM_MODE_MATCH_FLAGS |
+					    DRM_MODE_MATCH_3D_FLAGS))
 				can_clone = false;
 		}
 	}
@@ -2203,7 +2207,11 @@ static bool drm_target_cloned(struct drm_fb_helper *fb_helper,
 
 		fb_helper_conn = fb_helper->connector_info[i];
 		list_for_each_entry(mode, &fb_helper_conn->connector->modes, head) {
-			if (drm_mode_equal(mode, dmt_mode))
+			if (drm_mode_match(mode, dmt_mode,
+					   DRM_MODE_MATCH_TIMINGS |
+					   DRM_MODE_MATCH_CLOCK |
+					   DRM_MODE_MATCH_FLAGS |
+					   DRM_MODE_MATCH_3D_FLAGS))
 				modes[i] = mode;
 		}
 		if (!modes[i])
diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
index 219890f..79b2a24 100644
--- a/drivers/gpu/drm/drm_modes.c
+++ b/drivers/gpu/drm/drm_modes.c
@@ -1050,7 +1050,8 @@ bool drm_mode_equal(const struct drm_display_mode *mode1,
 			      DRM_MODE_MATCH_TIMINGS |
 			      DRM_MODE_MATCH_CLOCK |
 			      DRM_MODE_MATCH_FLAGS |
-			      DRM_MODE_MATCH_3D_FLAGS);
+			      DRM_MODE_MATCH_3D_FLAGS|
+			      DRM_MODE_MATCH_ASPECT_RATIO);
 }
 EXPORT_SYMBOL(drm_mode_equal);
 
@@ -1648,6 +1649,20 @@ void drm_mode_convert_to_umode(struct drm_mode_modeinfo *out,
 	out->vrefresh = in->vrefresh;
 	out->flags = in->flags;
 	out->type = in->type;
+
+	switch (in->picture_aspect_ratio) {
+	case HDMI_PICTURE_ASPECT_4_3:
+		out->flags |= DRM_MODE_FLAG_PIC_AR_4_3;
+		break;
+	case HDMI_PICTURE_ASPECT_16_9:
+		out->flags |= DRM_MODE_FLAG_PIC_AR_16_9;
+		break;
+	case HDMI_PICTURE_ASPECT_RESERVED:
+	default:
+		out->flags |= DRM_MODE_FLAG_PIC_AR_NONE;
+		break;
+	}
+
 	strncpy(out->name, in->name, DRM_DISPLAY_MODE_LEN);
 	out->name[DRM_DISPLAY_MODE_LEN-1] = 0;
 }
@@ -1692,6 +1707,24 @@ int drm_mode_convert_umode(struct drm_device *dev,
 	strncpy(out->name, in->name, DRM_DISPLAY_MODE_LEN);
 	out->name[DRM_DISPLAY_MODE_LEN-1] = 0;
 
+	/* Clearing picture aspect ratio bits from out flags,
+	 * as the aspect-ratio information is not stored in
+	 * flags for kernel-mode, but in picture_aspect_ratio.
+	 */
+	out->flags &= ~DRM_MODE_FLAG_PIC_AR_MASK;
+
+	switch (in->flags & DRM_MODE_FLAG_PIC_AR_MASK) {
+	case DRM_MODE_FLAG_PIC_AR_4_3:
+		out->picture_aspect_ratio |= HDMI_PICTURE_ASPECT_4_3;
+		break;
+	case DRM_MODE_FLAG_PIC_AR_16_9:
+		out->picture_aspect_ratio |= HDMI_PICTURE_ASPECT_16_9;
+		break;
+	default:
+		out->picture_aspect_ratio = HDMI_PICTURE_ASPECT_NONE;
+		break;
+	}
+
 	out->status = drm_mode_validate_driver(dev, out);
 	if (out->status != MODE_OK)
 		goto out;
-- 
2.7.4