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 4C4E83890F8 for ; Mon, 14 Sep 2026 18:42:42 +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=1789411363; cv=none; b=lx4rF08lxRWnLKx5Vhw1X+n3EaoREOrYKtmJo8lnw8C3QvykvpTWj8JDLBYyt9Fr9aR16AdALJFwtSFM3veduyXMiai14I/jiMv4kgEyU/p/ugwxHJdFeQ9M5H8ml2O/es4/h+x157SqSc+KFwg//Ly46SDl7M4NDpTZkTcMVhs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789411363; c=relaxed/simple; bh=FYOL3sCfuxjtmPM0TgOzhc5gXb6dGT1hUtNjBAX03AY=; h=From:To:Subject:Date:Message-ID:Content-Type:MIME-Version; b=CvQebmhn4pmQhOYhFv/RgqwZD/z7amJXASC9g1v0wmhavkADp4iG4mxceEd5P0XzC9dsgEYd0+eZJyZ+vQZSINF3xDRExN848DlMAomTII5hmKKRt3AHyPQoOOrVzsxtbVhcMLHxRcO0h9Wjq/zE6yHIgOunA9qlnJ44kFw/Tqw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=H5UvUqzh; 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="H5UvUqzh" Received: by smtp.kernel.org (Postfix) with ESMTPS id ACA42C2BCB8 for ; Mon, 14 Sep 2026 18:42:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1789411362; bh=FYOL3sCfuxjtmPM0TgOzhc5gXb6dGT1hUtNjBAX03AY=; h=From:To:Subject:Date:From; b=H5UvUqzhBy1NsKxk+sb8QbixQC18qwwmtVxsqxim392Ulw6fWBjP2cLUcmvDrruRi 0dS3lC8V2xgyKTQdHVzN9JYqfJ+z06KKSfLBdyMBAEgDdqvugNw7VKD4rgdt2o0ewi XhK6xkQa3suS09U/HfE8sda47b30choLbBaCCG8fRp98VlnuyMa//bLyu/zfZzQ1cf n6Y/3jgQ7zfxhxMazwtrY1DSnTHEuHzS3SjPwnkXb+4OE4RkrtwNa9Fyt7VyrMQeYK uEnMNpcjTMKZn/yYfT7Grx9ZLUxNbzHuKvIU4M8z5GAxgTlaG/MJ72YLHgGSOR8nkj n36gqjX8LZZoQ== Received: by aws-us-west-2-korg-bugzilla-1.web.codeaurora.org (Postfix, from userid 48) id 85D3CC41612; Mon, 14 Sep 2026 18:42:42 +0000 (UTC) From: bugzilla-daemon@kernel.org To: platform-driver-x86@vger.kernel.org Subject: [Bug 222015] New: ASUS TUF Gaming A18 (FA808UH): keyboard backlight requires HID feature report 0x46 0x01 to initialize on cold boot Date: Mon, 14 Sep 2026 18:42:42 +0000 X-Bugzilla-Reason: None X-Bugzilla-Type: new 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: imatvey.root@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: bug_id short_desc product version rep_platform op_sys bug_status bug_severity priority component assigned_to reporter cf_regression attachments.created Message-ID: 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=3D222015 Bug ID: 222015 Summary: ASUS TUF Gaming A18 (FA808UH): keyboard backlight requires HID feature report 0x46 0x01 to initialize on cold boot Product: Drivers Version: 2.5 Hardware: AMD OS: Linux Status: NEW Severity: normal Priority: P3 Component: Platform_x86 Assignee: drivers_platform_x86@kernel-bugs.osdl.org Reporter: imatvey.root@gmail.com Regression: No Created attachment 310851 --> https://bugzilla.kernel.org/attachment.cgi?id=3D310851&action=3Dedit dmesg Problem ------- Keyboard backlight (asus::kbd_backlight LED class device) does not work on a cold boot under Linux. Writing a brightness value to /sys/class/leds/asus::kbd_backlight/brightness succeeds and the value is reflected in the sysfs file, but the physical backlight stays off. This is reproducible on a vanilla Arch kernel (7.2.4-arch1-2) and was also observed on linux-zen, on a fully updated EndeavourOS installation. Hardware -------- System: ASUS TUF Gaming A18 FA808UH_FA808UH Board: FA808UH BIOS: FA808UH.313 (02/04/2026) CPU/GPU: AMD Ryzen + NVIDIA (ASUS TUF A18, 2025/2026 model) Root cause / evidence --------------------- 1. Booting Windows (bare metal, not a VM) turns the keyboard backlight on immediately. This proves the hardware and firmware are fine. 2. After a *warm reboot* from Windows into Linux, the backlight remains on and asusctl / brightnessctl start working normally. This shows that the embedded controller (EC) state is initialized by Windows and persists across a warm reboot. 3. On a *cold boot* directly into Linux, the EC is never initialized, so the LED class device accepts writes but they have no effect. 4. Sending a single HID feature report to the keyboard controller fixes the problem immediately and permanently for the rest of the boot session: hidapitester --vidpid 0B05/19B6 --open --send-feature 70,1 --close The tool writes a 64-byte feature report whose first two bytes are 0x46 0x01. After this, writing brightness to sysfs works as expected. Workaround ---------- A systemd oneshot service that runs hidapitester at boot restores normal behavior. This is not a real fix, only a userspace workaround. Request ------- Please add a quirk to asus-wmi (or hid-asus) to send the equivalent feature report (0x46 0x01) to USB device 0B05:19B6 during driver initialization on the ASUS TUF Gaming A18 FA808UH / FA808UP, so the keyboard backlight works out of the box on cold boot. Attachments ----------- I can provide the following if needed: - full dmesg from a cold boot - lsusb -v output for the keyboard device --=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.=