From nobody Mon Jun 8 20:42:41 2026 Received: from mx3.molgen.mpg.de (mx3.molgen.mpg.de [141.14.17.11]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 09CB51C860C for ; Tue, 26 May 2026 15:21:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=141.14.17.11 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779808889; cv=none; b=T+/9baRI+eDKnH+VczzAiBfjVB/6inWM2A42fSWirF5IdL8n+JKIgxsSCjrjp8yg3ZiW05v1hHM7grffI/kPr3BGvUXgRdjlJwLHUTEJnna/VwOFisrLkeOp3uUpqyb6Ik/YZjJZJ2cKDh7xmHTlhy4/MZM2Etf5pBy3Zz/172w= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779808889; c=relaxed/simple; bh=w/uEujQjIsungLxL/WiTn5w49KTrO+eZT1x1cdeWSUU=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type; b=gUP1w4EgAuMEN66ZvdQIZPBlpaJErl4YG3OUDpoSCydOhf5xZWREvF01h8amkkUnRf4BK7RXcbJKMkgYGuTfKHxbU3uX6n7Fr8zU5rxey7Yuqp96fwkpaqul0uQZtSO5GYQb1IM2CThIPnyC/A3CL5G7dE2qwhXS/bJIWg8grl0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=molgen.mpg.de; spf=pass smtp.mailfrom=molgen.mpg.de; arc=none smtp.client-ip=141.14.17.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=molgen.mpg.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=molgen.mpg.de Received: from abreu.molgen.mpg.de (g42.guest.molgen.mpg.de [141.14.220.42]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: pmenzel) by mx.molgen.mpg.de (Postfix) with ESMTPSA id 3E1A24C1A0B1B4; Tue, 26 May 2026 17:20:54 +0200 (CEST) From: Paul Menzel To: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter Cc: Paul Menzel , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH] drm/probe-helper: honour connector->force in drm_helper_probe_detect() Date: Tue, 26 May 2026 17:20:25 +0200 Message-ID: <20260526152025.12530-2-pmenzel@molgen.mpg.de> X-Mailer: git-send-email 2.53.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable With `video=3DDP-2:d drm.debug=3D0x04` the connectors are correctly forced off at init time: [9.742468] [drm] forcing DP-2 connector off but `intel_dp_detect()` is still called immediately after: [9.908738] [drm:intel_dp_detect] [CONNECTOR:130:DP-2] [9.912982] [drm:intel_hotplug_detect_connector] [CONNECTOR:130:DP-2] st= atus updated from unknown to unknown (epoch counter 0->1) `drm_helper_probe_single_connector_modes()` already short-circuits when `connector->force` is set, returning the forced status without calling any detect callbacks. `drm_helper_probe_detect()` however has no such guard, so callers that go through it directly =E2=80=93 such as i915's `intel_hotplug_detect_connector()` =E2=80=93 still run the full hardware pr= obe (AUX DPCD read, GMBus DDC transaction, =E2=80=A6) even when the user has forced a connector off via the `video=3D` command-line parameter. Add the same connector->force check at the top of `drm_helper_probe_detect()`, so that the hardware probe is skipped regardless of the entry point. This makes `video=3D:d` effective at boot time, not just for userspace `GETCONNECTOR` ioctls. This is tested on a Dell XPS 13 9360 (Intel Kaby Lake-U GT2 [HD Graphics 620] [8086:5916]). With `video=3DDP-2:d drm.debug=3D0x04`, Linux logs: [ 11.701243] [drm] forcing DP-2 connector off [ 11.701245] [drm:drm_connector_init_only [drm]] cmdline mode for con= nector DP-2 0x0@60Hz [=E2=80=A6] [ 12.102009] i915 0000:00:02.0: [drm:drm_helper_probe_detect [drm_kms= _helper]] [CONNECTOR:130:DP-2] force=3D1, skipping detect Assisted-by: Claude Sonnet 4.6 Signed-off-by: Paul Menzel --- drivers/gpu/drm/drm_probe_helper.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe= _helper.c index d4dc8cb45bce..bc513f24bc28 100644 --- a/drivers/gpu/drm/drm_probe_helper.c +++ b/drivers/gpu/drm/drm_probe_helper.c @@ -401,6 +401,17 @@ drm_helper_probe_detect(struct drm_connector *connecto= r, struct drm_device *dev =3D connector->dev; int ret; =20 + if (connector->force) { + drm_dbg_kms(dev, "[CONNECTOR:%d:%s] force=3D%d, skipping detect\n", + connector->base.id, connector->name, + connector->force); + if (connector->force =3D=3D DRM_FORCE_ON || + connector->force =3D=3D DRM_FORCE_ON_DIGITAL) + return connector_status_connected; + else + return connector_status_disconnected; + } + if (!ctx) return drm_helper_probe_detect_ctx(connector, force); =20 --=20 2.53.0