From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793661194; b=h+qol8M28zG1brS5fF8bxxTKnLvxnkSgTZWJLK4YWD8K0vipXS4YYBlTU7AaRd6ESLaQ iRhnca5jD4gG9WgzYsWSm7EWro47QOLyqbmtrPRA0X2FGyhrxdlircUBnigP2dNM0d0OT huUQ/ObrFeev8/WrQbPLSZ35s4a1H76PJoWAJjBMpfB0O/rMoz8FA/6iNQo+fgcksC4Nx /xaCnkVmWnsMujweKASUQ1cvzmnv22YdWQf4ig3U22pyUtDxh5m8M+seFR+cEUJO221hc 24q8EOK/Y0M1TxNvDfgSXXPdhQrFdYUDniG1K0R+vM7F6KSOODaJsAe2frvz8Bj1Low== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793661194; h=Received:DKIM-Signature:Message-ID:Date:MIME-Version:User-Agent: Subject:Content-Language:To:Cc:References:From:In-Reply-To: Content-Type:Content-Transfer-Encoding; bh=NPBPU5LdYVMPWjtAsxZva+V6uRvSmgSxT4p0WjPaiCg=; b=kzL/GXcML+YpxhR/eARKIKNwq3OdwZ3A8oT+XTNg5WuEUH3I7g8R7tuPjwHCkK6s8yQA J+UtnbJX/iyXtnoD5LI9oq3dH4LfeNREGRo8xFkIeftAecex+0izJ8Pw6YUgRjKMiaxp4 4dQhmO6HuYg4fl8Fz12Fbts4hbbxTpdJKrHcUkm6CSBIpM3bQN5ZobF9R9FvQwndEuo52 KqHxleTd2zABb/6kUnU6pZ/O9KIb4bbtbjyZ/xrX7X5QXhrpI0w/VsF5x3TSlEUqY+Nvu D+SmYrCaHU8WPwBN56X8ygM42CvBTQJGnRDjLDOsBsmCKsvSIK4yLVxFDsIOshbRKdQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=GrAw74ky; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9FB06606A326 for ; Mon, 2 Nov 2026 23:13:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=GrAw74ky Received: by smtp.kernel.org (Postfix) with ESMTPSA id 686091F00A16; Mon, 2 Nov 2026 23:13:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793661193; bh=NPBPU5LdYVMPWjtAsxZva+V6uRvSmgSxT4p0WjPaiCg=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=GrAw74kyO365Lj29y9D5jygW2kHYe+aLmYiE8a0wGEYsCeTi+Z2RanjZvFUxFQ0R/ +Cs1ojK33TqDlTMzuU5hMJONd2/3ARrUbIghxgiZ9DrJB0XYPDNQgyiOXw42+/p7ja 0+9bfcMlxjlVjQOi8+A82E5KHqaiSeCOYrTqspPlTcMoklGcSGf7yrGYfuA3jiT5yJ HqY6DQxwB0Y9O0xgneqzlTTNExPMI712qe8BZw/R/bMKHiDbDOsHf5P2gOCst2Aqji GY9qEYjRMfXoeP/OZgBGYIz7QgqmPtfLj+3ambJZKkirj3TysJJR4BaLFVZBO2ZkhP OwDQ4sy6HnAUw== Message-ID: <7b87b864-7896-4260-aad6-a78687201c0f@kernel.org> Date: Mon, 2 Nov 2026 17:13:10 -0600 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] drm: panel-backlight-quirks: Add ASUS ROG Flow X13 3840x2400 panel Content-Language: en-US To: Hugo Sales , maarten.lankhorst@linux.intel.com, mripard@kernel.org, tzimmermann@suse.de, dri-devel@lists.freedesktop.org Cc: airlied@gmail.com, simona@ffwll.ch, alexander.deucher@amd.com, harry.wentland@amd.com, amd-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org References: <20261031134551.2735792-1-hugo@hsal.es> From: Mario Limonciello In-Reply-To: <20261031134551.2735792-1-hugo@hsal.es> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 10/31/26 08:45, Hugo Sales wrote: > On an ASUS ROG Flow X13 GV301QH (BIOS 418) ATIF > QUERY_BACKLIGHT_TRANSFER_CHARACTERISTICS answers with a minimum input > signal of 12 and 49 curve points for the Sharp LQ134R1JW51 panel, and > amdgpu logs "Using custom brightness curve". With that minimum, > brightness 0 gives 4.7% duty > > With the quirk, brightness 0 sends PWM 0 (read back from > amdgpu_current_backlight_pwm in debugfs). The panel stays lit, but much > dimmer than the old 4.7% floor. Its LED driver has a minimum of its own, > so 0 does not turn the backlight off > > linux-hardware.org also lists this panel in a GV301QE. Match the ASUS > vendor and the panel, as the Framework 13 entries do, and let the > brightness reach the bottom of the PWM range > > Signed-off-by: Hugo Sales > --- > I could only test this on a GV301QH. The entry matches any ASUS laptop > with this panel, and linux-hardware.org only lists it in ROG Flow X13s, > one of them a GV301QE. If you'd rather limit it to the GV301QH, I can > add a DMI_BOARD_NAME match in v2 > > drivers/gpu/drm/drm_panel_backlight_quirks.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/drivers/gpu/drm/drm_panel_backlight_quirks.c b/drivers/gpu/drm/drm_panel_backlight_quirks.c > index 2d0238382ebd5..b60333e748741 100644 > --- a/drivers/gpu/drm/drm_panel_backlight_quirks.c > +++ b/drivers/gpu/drm/drm_panel_backlight_quirks.c > @@ -69,6 +69,14 @@ static const struct drm_get_panel_backlight_quirk drm_panel_min_backlight_quirks > .dmi_match_other.value = "Galileo", > .quirk = { .min_brightness = 1, }, > }, > + /* ASUS ROG Flow X13 3840x2400 panel */ > + { > + .dmi_match.field = DMI_SYS_VENDOR, > + .dmi_match.value = "ASUSTeK COMPUTER INC.", > + .ident.panel_id = drm_edid_encode_panel_id('S', 'H', 'P', 0x151b), > + .ident.name = "LQ134R1JW51", > + .quirk = { .min_brightness = 1, }, > + }, > /* Have OLED Panels with brightness issue when last byte is 0/1 */ > { > .dmi_match.field = DMI_SYS_VENDOR, Was this from looking at a datasheet or from empirical measurements? The reason it was safe to do on the Framework panel was because there was a confirmation the datasheet allowed a lower value. We don't want to be damaging hardware running it outside of spec.