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 AFA22218E91 for ; Tue, 2 Jun 2026 13:44:46 +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=1780407886; cv=none; b=jpngCW6n6dkJTtT43ZjYVB+JIKzEcy37d48TGQZ+IhYM7QCrLjDGnzR77zIg1C6JCRSG/EZmT19SxVcDObB3Tt/J+sWZz1AakM8RIulqUeSIiK381GiSUjVRmcuuNnJILgl2YVFxcH2wFWhBDrVZ9a9ZbRwmkVqJOmvKBVRj9eA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780407886; c=relaxed/simple; bh=F/Vjd7DwhsmQc/OBuzcxWiKxsRLdvpiZ/w/DVsHjf/Y=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: Content-Type:MIME-Version; b=rQW5APW8lJ7utdOJwDCad4QHNHDI1B3AEw9wzVjONOddoo2dRqJItQUew604D8VR2TS0/u8HMXKlN3QdUAgBezl68T3NQybiyUmW8SczJZyE2OhKEggfQyWlRbJpeRy807EbySVagSwccerHumsx1sdJG16inpJg5fkeVjNmWKc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=OWgF9tw2; 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="OWgF9tw2" Received: by smtp.kernel.org (Postfix) with ESMTPS id 88EAAC2BCC4 for ; Tue, 2 Jun 2026 13:44:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1780407886; bh=F/Vjd7DwhsmQc/OBuzcxWiKxsRLdvpiZ/w/DVsHjf/Y=; h=From:To:Subject:Date:In-Reply-To:References:From; b=OWgF9tw2vJmvusnUZhzh5rGcGajMkfC/1BAKdU01G6MA77fHaDisqyvvG9zAy8fPX H342Tc91N23AmGa4U5cAnte7ONzyhst13xN+60qOcDa7KneOOJqmQ/Z8cNhJH0U8eQ qsUYssmvNtUpI3lkZ325aJpYyZcbULMV7DBKkHVaTv6dkYtzkb9QgHxmtDTijKeNM3 SvHxT/PymkvHshUwH3zi4oiCae5lN6qDzWayncpjvAEzolFSFbH54LJsc4eShIX466 Jw3jBV0d/36EdRrN9ABTBL4K9A35n9z8T9/Z7E4G28ZFaBKUckvu2ymRMnYmbIbB6D XsWi5bhdA8phg== Received: by aws-us-west-2-korg-bugzilla-1.web.codeaurora.org (Postfix, from userid 48) id 77774C4160E; Tue, 2 Jun 2026 13:44:46 +0000 (UTC) From: bugzilla-daemon@kernel.org To: platform-driver-x86@vger.kernel.org Subject: [Bug 221583] Lenovo 82KU: keyboard backlight works via Fn+Space but no kbd_backlight LED device exposed Date: Tue, 02 Jun 2026 13:44:46 +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: i@rong.moe 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=3D221583 --- Comment #3 from Rong Zhang (i@rong.moe) --- (In reply to George from comment #2) > HALS: 0x0000ca40 Your device reports itself as no keyboard backlight support. >=20 > I cycled the keyboard backlight through all states using Fn+Space (Off = =E2=86=92 Low > =E2=86=92 High =E2=86=92 Off), then compared the contents of both files b= efore and after: >=20 > ```text > $ diff -u ~/cfg-before.txt ~/cfg-after.txt > $ diff -u ~/status-before.txt ~/status-after.txt > ``` >=20 > Both commands produced no output. Sorry, I meant you would need to check for content changes each time Fn+Spa= ce is pressed, i.e., Off =E2=86=92 Low, Low =E2=86=92 High, High =E2=86=92 Off. > I have attached `acpidump.txt.gz`. The HALS method seems to lack keyboard backlight stuff. But the SALS method= can be used to set a two-level backlight brightness (off, on), interesting. No other ACPI method for keyboard backlight is found. --=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.=