linux-kernel - [PATCH 4/9] drm/bridge: lontium-lt9611: handle unsupported InfoFrames

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Message-Id: <20250927-limit-infoframes-2-v1-4-697511bd050b@oss.qualcomm.com>
Date: Sat, 27 Sep 2025 04:04:33 +0300
From: Dmitry Baryshkov <dmitry.baryshkov@....qualcomm.com>
To: Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
        Maxime Ripard <mripard@...nel.org>,
        Thomas Zimmermann <tzimmermann@...e.de>,
        David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>,
        Liu Ying <victor.liu@....com>, Andrzej Hajda <andrzej.hajda@...el.com>,
        Neil Armstrong <neil.armstrong@...aro.org>,
        Robert Foss <rfoss@...nel.org>,
        Laurent Pinchart <Laurent.pinchart@...asonboard.com>,
        Jonas Karlman <jonas@...boo.se>,
        Jernej Skrabec <jernej.skrabec@...il.com>,
        Rob Clark <robin.clark@....qualcomm.com>,
        Dmitry Baryshkov <lumag@...nel.org>,
        Abhinav Kumar <abhinav.kumar@...ux.dev>,
        Jessica Zhang <jessica.zhang@....qualcomm.com>,
        Sean Paul <sean@...rly.run>,
        Marijn Suijten <marijn.suijten@...ainline.org>,
        Sandy Huang <hjc@...k-chips.com>,
        Heiko Stübner <heiko@...ech.de>,
        Andy Yan <andy.yan@...k-chips.com>, Chen-Yu Tsai <wens@...e.org>,
        Samuel Holland <samuel@...lland.org>
Cc: dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
        linux-arm-msm@...r.kernel.org, freedreno@...ts.freedesktop.org,
        linux-arm-kernel@...ts.infradead.org,
        linux-rockchip@...ts.infradead.org, linux-sunxi@...ts.linux.dev
Subject: [PATCH 4/9] drm/bridge: lontium-lt9611: handle unsupported
 InfoFrames

Make hdmi_write_hdmi_infoframe() and hdmi_clear_infoframe() callbacks
return -EOPNOTSUPP for unsupported InfoFrames and make sure that
atomic_check() callback doesn't allow unsupported InfoFrames to be
enabled.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@....qualcomm.com>
---
 drivers/gpu/drm/bridge/lontium-lt9611.c | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/bridge/lontium-lt9611.c b/drivers/gpu/drm/bridge/lontium-lt9611.c
index a2d032ee4744715b88eb66883edf69bab4c274b0..9c2c9887d2d66968eb1d50544a257d5999bbdded 100644
--- a/drivers/gpu/drm/bridge/lontium-lt9611.c
+++ b/drivers/gpu/drm/bridge/lontium-lt9611.c
@@ -869,9 +869,7 @@ static int lt9611_hdmi_clear_infoframe(struct drm_bridge *bridge,
 		break;
 
 	default:
-		drm_dbg_driver(lt9611->bridge.dev, "Unsupported HDMI InfoFrame %x\n", type);
-		mask = 0;
-		break;
+		return -EOPNOTSUPP;
 	}
 
 	if (mask)
@@ -910,9 +908,7 @@ static int lt9611_hdmi_write_infoframe(struct drm_bridge *bridge,
 		break;
 
 	default:
-		drm_dbg_driver(lt9611->bridge.dev, "Unsupported HDMI InfoFrame %x\n", type);
-		mask = 0;
-		break;
+		return -EOPNOTSUPP;
 	}
 
 	if (mask) {
@@ -925,6 +921,19 @@ static int lt9611_hdmi_write_infoframe(struct drm_bridge *bridge,
 	return 0;
 }
 
+static int lt9611_bridge_atomic_check(struct drm_bridge *bridge,
+				      struct drm_bridge_state *bridge_state,
+				      struct drm_crtc_state *crtc_state,
+				      struct drm_connector_state *conn_state)
+{
+	/* should not happen, HDR support not enabled */
+	if (drm_WARN_ON_ONCE(bridge->encoder->dev,
+			     conn_state->hdmi.infoframes.hdr_drm.set))
+		return -EOPNOTSUPP;
+
+	return 0;
+}
+
 static enum drm_mode_status
 lt9611_hdmi_tmds_char_rate_valid(const struct drm_bridge *bridge,
 				 const struct drm_display_mode *mode,
@@ -993,6 +1002,7 @@ static const struct drm_bridge_funcs lt9611_bridge_funcs = {
 	.edid_read = lt9611_bridge_edid_read,
 	.hpd_enable = lt9611_bridge_hpd_enable,
 
+	.atomic_check = lt9611_bridge_atomic_check,
 	.atomic_pre_enable = lt9611_bridge_atomic_pre_enable,
 	.atomic_enable = lt9611_bridge_atomic_enable,
 	.atomic_disable = lt9611_bridge_atomic_disable,

-- 
2.47.3