From nobody Fri Jun 19 07:53:07 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 92854364925; Sun, 26 Apr 2026 14:08:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777212530; cv=none; b=Cpp8KMGFZia1urGfVwxxhNk3XKbs3DiVBOms6RiS8ioHb5peq5oM4BNwubR2TOjmOD+IQerK2x/iyxHsY4V0ccv66ANEa6WeZ0ip2HHCIeuf6C0dyoAmQ8b1113SAr5WL96jKPNV72dEs+W/NFXwFN3zfNU6EgQbsnwtt+FbqIc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777212530; c=relaxed/simple; bh=Aqi75IhndrV0ywUutOkCqgNS6SouxMp0XDzJxatZjrY=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=l/1vukUg36u4TL5JvuSVmdTCQPF58pwLjIR+dom9Cs6ShNMBWgDgxTHhkltoTcBOZufShxHwdibf5Wr9TFzbVCnUJdV2+hGXY0mMrXYQoR4mFKv5IWgRdUUV5x5/LoYzFrUNbxJEqZRj4ZjkmmjBrzpWPO44XFlIZW+IkXbT7RU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=XYY6jPZ7; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="XYY6jPZ7" Received: by smtp.kernel.org (Postfix) with ESMTPS id 3BE8AC2BCB3; Sun, 26 Apr 2026 14:08:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777212530; bh=Aqi75IhndrV0ywUutOkCqgNS6SouxMp0XDzJxatZjrY=; h=From:Date:Subject:To:Cc:Reply-To:From; b=XYY6jPZ7QSASe7snmeFwrM6pHNhkv0AOZMZfyK1IZeF4b83hT23HfVmanvwmi4Z+a /rNG8bx4Fyhy4osjwp9yPgblAhg0vDgFxLRMvmVUs3TjWe9PV0UsB0DgrwxLOfVDud +EqQ8xJNbCENQtbG6/iIeOItrQ/sCTeUVsDIcxJOIqTmeV2Tl5hOwPd/zHSKobXw+i cO4N5/BL6v4cbgUWVfDEu6NFHloHaw9lfdDHWMpN+rJOUvMIf/e9qBKNt8TQevNe3T Zd2W1765QXV7FYqPLP3h9FE1a38LS+VnVT73d8CHzBvFG2pLLB5p2ecTbs8P+2jwSZ XGBK60af56tSw== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2DD02FF885E; Sun, 26 Apr 2026 14:08:50 +0000 (UTC) From: Shivam Kalra via B4 Relay Date: Sun, 26 Apr 2026 19:38:41 +0530 Subject: [PATCH] ACPI: video: force native backlight on HP OMEN 16 (8A44) 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 Message-Id: <20260426-omen-16-backlight-fix-v1-1-62364f268ea6@zohomail.in> X-B4-Tracking: v=1; b=H4sIAGgc7mkC/yXM0Q5DQBCF4VeRuTYJS1Gv0rjYWYPRdjW7iES8u y2X30nOv4NnJ+yhjnZwvIqXyQakcQRm0LZnlDYYVKKKJFcPnL5sMS2QtHl/pB9m7GTDMuuoIpN rRU8I35/jMF/dV3PbLzSymf8xOI4TdT+L03kAAAA= X-Change-ID: 20260425-omen-16-backlight-fix-73fb8bc4a2b9 To: "Rafael J. Wysocki" , Len Brown Cc: linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Shivam Kalra X-Mailer: b4 0.15.1 X-Developer-Signature: v=1; a=ed25519-sha256; t=1777212528; l=3008; i=shivamkalra98@zohomail.in; s=20260402; h=from:subject:message-id; bh=Ks75/0yCMSiPZ5NGPSiLdDntV/e7UFJBadOo45wysJA=; b=ImzlN1NF/yjSEwdic/vHSQlDyh2HDbuxm3ilC7wHeE26rJSBVCMfn4V3XByKns2e2Sekc/Yrj AA+AbNfO0kDAJPvHDEDPFsh+D+binV7lvoEReIkEwJGdwwIhdYKWZAB X-Developer-Key: i=shivamkalra98@zohomail.in; a=ed25519; pk=U8kQSxcte8P8iZ6zB7phIj+Yl+i/5ntifBGuclgypx8= X-Endpoint-Received: by B4 Relay for shivamkalra98@zohomail.in/20260402 with auth_id=716 X-Original-From: Shivam Kalra Reply-To: shivamkalra98@zohomail.in From: Shivam Kalra The HP OMEN 16 Gaming Laptop (board name 8A44) has a mux-less hybrid GPU configuration with AMD Rembrandt (Radeon 680M) and NVIDIA GA104 (RTX 3070 Ti). The internal eDP panel is wired to the AMD iGPU. When Nouveau loads without GSP firmware, the ACPI video backlight device (acpi_video0) gets registered alongside the native AMD backlight (amdgpu_bl2). In this state, writes to amdgpu_bl2 update the software brightness value but fail to change the physical panel brightness. Force native backlight to prevent acpi_video0 from registering. Confirmed that booting with acpi_backlight=3Dnative resolves the issue. Cc: stable@vger.kernel.org Signed-off-by: Shivam Kalra --- This patch adds a DMI quirk to force native backlight control on the HP OMEN 16 Gaming Laptop (board name 8A44), which has a mux-less hybrid GPU configuration with AMD Rembrandt (680M iGPU) and NVIDIA GA104 (RTX 3070 Ti). On this laptop the internal eDP panel is wired to the AMD iGPU. The amdgpu driver registers amdgpu_bl2 as the native backlight device. When the Nouveau driver is loaded without GSP firmware (as is the case on v6.17 where GSP is not the default for Ampere GPUs), writes to amdgpu_bl2 fail silently =E2=80=94 the brightness sysfs value updates but the physical panel brightness does not change. Testing: - Tested on HP OMEN 16 with AMD Ryzen 9 6900HX + NVIDIA RTX 3070 Ti. - On v6.17, without this quirk, brightness control is broken. - On v6.17, booting with acpi_backlight=3Dnative restores correct brightness control. This patch applies that workaround automatically via DMI match. - On v6.18+, the issue does not reproduce because commit e0ed674acbac ("drm/nouveau: Remove DRM_NOUVEAU_GSP_DEFAULT config") made GSP firmware the default for Ampere, which avoids the ACPI conflict entirely. =20 I have only tested this on v6.17 and v7.0. I am leaving it to the stable/LTS maintainers to determine whether this quirk should be backported, as I have not verified the stability of the GSP firmware path on intermediate releases. Thanks, Shivam Kalra --- drivers/acpi/video_detect.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c index 0a3c8232d15d..458efa4fe9d4 100644 --- a/drivers/acpi/video_detect.c +++ b/drivers/acpi/video_detect.c @@ -916,6 +916,14 @@ static const struct dmi_system_id video_detect_dmi_tab= le[] =3D { DMI_MATCH(DMI_PRODUCT_NAME, "82K8"), }, }, + { + .callback =3D video_detect_force_native, + /* HP OMEN Gaming Laptop 16-n0xxx */ + .matches =3D { + DMI_MATCH(DMI_SYS_VENDOR, "HP"), + DMI_MATCH(DMI_PRODUCT_NAME, "OMEN by HP Gaming Laptop 16-n0xxx"), + }, + }, =20 /* * x86 android tablets which directly control the backlight through --- base-commit: 27d128c1cff64c3b8012cc56dd5a1391bb4f1821 change-id: 20260425-omen-16-backlight-fix-73fb8bc4a2b9 Best regards, -- =20 Shivam Kalra