linux-kernel - [PATCH] drm/display: hdmi: Do not read EDID on disconnected connectors

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-Id: <20250111-hdmi-conn-edid-read-fix-v1-1-d68361624380@collabora.com>
Date: Sat, 11 Jan 2025 00:04:09 +0200
From: Cristian Ciocaltea <cristian.ciocaltea@...labora.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>, 
 Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
Cc: kernel@...labora.com, dri-devel@...ts.freedesktop.org, 
 linux-kernel@...r.kernel.org
Subject: [PATCH] drm/display: hdmi: Do not read EDID on disconnected
 connectors

The recently introduced hotplug event handler in the HDMI Connector
framework attempts to unconditionally read the EDID data, leading to a
bunch of non-harmful, yet quite annoying DDC/I2C related errors being
reported.

Ensure the operation is performed only for connectors having the status
connected or unknown.

Fixes: ab716b74dc9d ("drm/display/hdmi: implement hotplug functions")
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@...labora.com>
---
 drivers/gpu/drm/display/drm_hdmi_state_helper.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/display/drm_hdmi_state_helper.c b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
index 2691e8b3e480131ac6e4e4b74b24947be55694bd..8e4b30e09b53b84cfd36199d56db3221a00085b0 100644
--- a/drivers/gpu/drm/display/drm_hdmi_state_helper.c
+++ b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
@@ -786,8 +786,10 @@ drm_atomic_helper_connector_hdmi_update(struct drm_connector *connector,
 	const struct drm_edid *drm_edid;
 
 	if (status == connector_status_disconnected) {
+		drm_edid_connector_update(connector, NULL);
 		// TODO: also handle CEC and scramber, HDMI sink disconnected.
 		drm_connector_hdmi_audio_plugged_notify(connector, false);
+		return;
 	}
 
 	if (connector->hdmi.funcs->read_edid)

---
base-commit: 1854df7087be70ad54e24b2e308d7558ebea9f27
change-id: 20250110-hdmi-conn-edid-read-fix-178513c2b7ea