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 6B84131A813 for ; Wed, 21 Jan 2026 01:50:18 +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=1768960218; cv=none; b=iqsSzvPXBNzzRb85ABl17UcvRxBxof1rUxVzvlkVABiLvqOMmyhdrBfz5vqKudCO1Ki6F+3VdGIppJFroyKwiV764a3rtE/Y3REU/hH3JYWHeqq5hAvEMGileIqFZjyheya5CX62hPnhpDapwxO3Y0eZVWARWx2ovviUvbxSNwY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768960218; c=relaxed/simple; bh=Thfnk7hhLKAH4QnFmRTMBcAqf5B0i4FHVNL/1qlV5+g=; h=From:To:Subject:Date:Message-ID:Content-Type:MIME-Version; b=YQwamSa15cXXVrfy4Q2ns3lRMqmmmqdZL5Fx6erVhpuxtMrU1A72GpNUmftyn676V6G1ZGc5ihbyocJliBqOXZZG+W3962GSrQ4Ifr1rTzFwVuTyv/ZHGhHYT1oCz/wPntUZ6sHPEMnu0+MSsaQoGfNoIybGpKMJRYx5atrWCVI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=eYKVkAtY; 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="eYKVkAtY" Received: by smtp.kernel.org (Postfix) with ESMTPS id CB8CEC19425 for ; Wed, 21 Jan 2026 01:50:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1768960217; bh=Thfnk7hhLKAH4QnFmRTMBcAqf5B0i4FHVNL/1qlV5+g=; h=From:To:Subject:Date:From; b=eYKVkAtY8mePPRb2yw9nIX1RmpNhod9owXG2+aXHMuJmEk/CRz2cZKGe7UKmPNfCD THu/y0ygViM9cIWoJv8YQu/wKsKOLqnLvU3RNQHkyV5VBCNR77icFYGuP+PGkHybKM 7Z+BrlTZjk6AKD6OXYHAoO5CYYdAbzgROSWNtTrr6ImmT947/AMwDRCnGzN7VAQTbI btkzOr4CX1qWh8bxqPOH2/79jONSWWJwaMY2riP//BGxF6z/9UMP/UxtZxoAnp7KuX tcOXf75YHgBqO4AhqyCfOPi5YBSt66CoyZDDrHDUVV7Mg/VWp2m4nRYIwuCCrFEMnt R6orDud57noog== Received: by aws-us-west-2-korg-bugzilla-1.web.codeaurora.org (Postfix, from userid 48) id C21F1C41616; Wed, 21 Jan 2026 01:50:17 +0000 (UTC) From: bugzilla-daemon@kernel.org To: platform-driver-x86@vger.kernel.org Subject: [Bug 220999] New: ASUS ExpertBook B1402CVA: Keyboard backlight brightness range incorrect (max=3, dim light) Date: Wed, 21 Jan 2026 01:50:17 +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: low X-Bugzilla-Who: stefano.pascale04@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=3D220999 Bug ID: 220999 Summary: ASUS ExpertBook B1402CVA: Keyboard backlight brightness range incorrect (max=3D3, dim light) Product: Drivers Version: 2.5 Hardware: All OS: Linux Status: NEW Severity: low Priority: P3 Component: Platform_x86 Assignee: drivers_platform_x86@kernel-bugs.osdl.org Reporter: stefano.pascale04@gmail.com Regression: No Created attachment 309219 --> https://bugzilla.kernel.org/attachment.cgi?id=3D309219&action=3Dedit output of `dmidecode` Hardware: ASUS ExpertBook B1402CVA Kernel Version: 6.18.5-200.fc43.x86_64 (Fedora Rawhide) CPU: 12 =C3=97 13th Gen Intel=C2=AE Core=E2=84=A2 i5-1335U Description: The keyboard backlight on this laptop is not working correctly with the asus-wmi driver. The system detects a `max_brightness` of 3. When setting brightness to 3, t= he keyboard lights up but only at a very dim level (barely visible). Setting i= t to 1 or 2 turns it off completely. It appears the hardware expects a range of 0-255 (or similar high value), b= ut the driver is limiting it to 0-3, possibly due to a missing quirk for this specific model ID in the WMI driver. Here is the sysfs output confirming the issue: $ grep . /sys/class/leds/asus::kbd_backlight/* /sys/class/leds/asus::kbd_backlight/brightness:0 /sys/class/leds/asus::kbd_backlight/brightness_hw_changed:0 /sys/class/leds/asus::kbd_backlight/max_brightness:3 /sys/class/leds/asus::kbd_backlight/trigger:[none] usb-gadget usb-host rc-feedback kbd-scrolllock kbd-numlock kbd-capslock ... (truncated) Steps to reproduce: 1. Boot Fedora 43 (Kernel 6.18). 2. Check /sys/class/leds/asus::kbd_backlight/max_brightness (Output is 3). 3. Set brightness to 3 (echo 3 | sudo tee ...). Result: Very dim light. Troubleshooting attempted: 1. Tried boot param `acpi_osi=3D` and `acpi_osi=3D"Windows 2020"` -> No cha= nge. 2. Tried `acpi_backlight=3Dnative` -> No interface created. 3. Tried `asusctl` -> Failed to set higher values. 4. Manually echoing values > 3 into 'brightness' -> No change. Attached is the output of `dmidecode`. I suspect this model needs a quirk in `drivers/platform/x86/asus-wmi.c` to enable the correct brightness range. --=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.=