From mboxrd@z Thu Jan 1 00:00:00 1970 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 97C503E5ED1 for ; Fri, 15 May 2026 10:01:06 +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=1778839266; cv=none; b=ONVoYYCJvDT3SDJhg8m6PDQtrkcF+pzDaVdZASghvug8jCkeiXlyTq9toFlhfq/l7JmP5Jr5SGvf4jmz4VRov2CV/+vjMdJXg2WAHnFo6DkjxL0y/RIcDFlIeWGxKD09EOgI9RY7SDSzxWg0i1cIB9kikXUlWkIKLls2QoraHXw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778839266; c=relaxed/simple; bh=LEYUM4yeOoSDXzQz/K8trPuSx559dqA05k4tJdu1IE0=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: Content-Type:MIME-Version; b=PC1u5rYCfsAkL8VhZgFZ/Ig1zltNMalbOV04MQDtHveflWFd52xjwKr1mQoUz3WSdzpHWgG1L1N4Ez9R6jQWhj21VM5E3d8ZzzI27KqO9ejRpeVlMXY93AN2e+n808iDjRf+1bogmXohvGRFA+ZfQ8MawPo8p3cn+GMbiMCsYDc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=rMrxtvGD; 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="rMrxtvGD" Received: by smtp.kernel.org (Postfix) with ESMTPS id 7A8AAC2BCB0 for ; Fri, 15 May 2026 10:01:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778839266; bh=LEYUM4yeOoSDXzQz/K8trPuSx559dqA05k4tJdu1IE0=; h=From:To:Subject:Date:In-Reply-To:References:From; b=rMrxtvGDPRJ7V1hzGAdWXhsSJ77WPICyzCwqD4jmLFLi3CBkON2QyZLygFW1ehrbt LnW6yCCRIIl5awHIBUOPF7HLiegf0L0zJ3XwRdD6ZiqbnRvvZl6YpxTNoUGEZ8Cpbw 3omA8YtFWkcjvWMdl9PW67ZAgmPwVt1GZsSLkSHhHMeRXMh53elOiVxVpJmZ6TiKau vKxk/AH97Q/sOiFcK50dTOB0xjifAzHJ3sjnfld0K5wxbFFAH/P7kERDW7F+i0CHpW wZqwTNwexBINmTH2Ez5qMUAjZ5JW9fHkwA/nQ0LKwvXxNTKdiaf0BEzPdIXBWiyfb1 Uknbv9bvyi1CQ== Received: by aws-us-west-2-korg-bugzilla-1.web.codeaurora.org (Postfix, from userid 48) id 6A76BC41612; Fri, 15 May 2026 10:01:06 +0000 (UTC) From: bugzilla-daemon@kernel.org To: platform-driver-x86@vger.kernel.org Subject: [Bug 221430] nvidia_wmi_ec_backlight: brightness writes silently dropped on HP OMEN 16 (2025) Date: Fri, 15 May 2026 10:01:06 +0000 X-Bugzilla-Reason: None X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: AssignedTo drivers_platform_x86@kernel-bugs.osdl.org X-Bugzilla-Product: Drivers X-Bugzilla-Component: Platform_x86 X-Bugzilla-Version: 2.5 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: floquimaurice@gmail.com X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: drivers_platform_x86@kernel-bugs.osdl.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugzilla.kernel.org/ Auto-Submitted: auto-generated Precedence: bulk X-Mailing-List: platform-driver-x86@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 https://bugzilla.kernel.org/show_bug.cgi?id=3D221430 --- Comment #12 from floquimaurice@gmail.com --- Hi, I opened a ticket with the Intel DRM team, and they analyzed the drm.debug= =3D0xe logs. https://gitlab.freedesktop.org/drm/i915/kernel/-/work_items/16065 They confirmed that the VBT correctly points to PCH PWM, and the i915 drive= r is doing its job perfectly. The logs show the driver successfully calculating = and sending the PWM updates to the registers (set backlight level =3D 98259). However, the physical panel ignores it. The Intel developers concluded this= is not an i915 issue. The hardware is deliberately ignoring the PCH PWM regist= ers, which perfectly confirms your initial theory: the HP Embedded Controller is waiting for the \_SB.PC00.GFX0.CBL1 ACPI trigger to release the backlight control. Now that Intel has officially bounced the ball back to the ACPI/firmware si= de, how can we proceed? --=20 You may reply to this email to add a comment. You are receiving this mail because: You are watching the assignee of the bug.=