From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=80.241.56.171 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793665815; b=2fQtXyzmpU7UGGnLBJXpYi2qfmjseDYQpkibIX7aLgdJYCmOO3sQ0yiqfGx6TGDcZr65 r+D2YnAViPEiv1f0fLepSr3jbCacCS3G14P5+36nKWSdOnXvDGJv4ZKhwjUIVknPXRT2w GXYvJFwyaMLpRwE61uMYd/+lcuKv8LwCpJDXorsEVNT9P19bLnnlQ4oCF5VPp7O3anO5s 9Pi4bPUsz1Y10ZUanNDB+Kbug7CfEItZzczoGwpFoe4GM68MEQO3OQyzl9q/7nlv73PsJ hk7I1RyoL1cvuUyaHF2WeFbMvBtfrNwg2x22h5ig/GuNTRuPwvacOnSOwUdrET2kT7Q== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793665815; h=DMARC-Filter:Received:DKIM-Signature:Date:From:To:Cc:Message-ID: In-Reply-To:References:Subject:MIME-Version:Content-Type: Content-Transfer-Encoding:X-Priority:Importance:X-Mailer: X-Originating-Client:X-Rspamd-Queue-Id; bh=VJ8awdZJyu03pjP9iovo5hQpWlX7slf0qi7xPXVtajA=; b=phFOQwmOxaICeNThQPqh3reVtN3QOhmV0SIehdqF8n86mwe0knuQBQTjFQGzBXkLrbM5 M5grnLP+ax/ij6D+juvXXvIttqDu+tBKK11dr7L2VDEjSmhmXpS0cf8v6P9QNmwSy0zav eSuIBm67QA45Or2b4MCd2lSysZTbaCrzGWkRVqWvaZay1+DUxwC0+/1bQDBKTQPZrIa4t i5k0UvYUlmo+D72wkZlrD7Y+27ubJNMiVsJjOdN3HktK4fV7F2CzJEqen5npPYh2tlzOY Z4CBlE1vnq6V8EykvkDGAzirBSJEmO2AzDBhyrlkmYW9xBxGvv7Tbnt6mat0tk9XAwQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=hsal.es; spf=pass smtp.mailfrom=hsal.es; dkim=pass header.d=hsal.es header.i=@hsal.es header.a=rsa-sha256 header.s=MBO0001 header.b=Z09T2qsg; arc=none smtp.remote-ip=80.241.56.171 Received: from mout-p-201.mailbox.org (mout-p-201.mailbox.org [80.241.56.171]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C07F6606A324 for ; Tue, 3 Nov 2026 00:30:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org C07F6606A324 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=hsal.es Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=hsal.es Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=hsal.es header.i=@hsal.es header.a=rsa-sha256 header.s=MBO0001 header.b=Z09T2qsg Received: from smtp1.mailbox.org (smtp1.mailbox.org [IPv6:2001:67c:2050:b231:465::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519MLKEM768 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-201.mailbox.org (Postfix) with ESMTPS id 4jJTx85RhZzMlSl; Tue, 03 Nov 2026 01:30:04 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=hsal.es; s=MBO0001; t=1793665804; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=VJ8awdZJyu03pjP9iovo5hQpWlX7slf0qi7xPXVtajA=; b=Z09T2qsg5HfQxmjIDZeJjVC28sQdKrhhW4Skzi4s6YnEtEzCVZtROZ/EIE/Ypr/t/jT/cT Nph0AAy/qA5gZB5X2W8ZWpEtC/jYuMxHfsLBXbo7k0ARNkD3rCkF7r9zhzKf97l1lTsKK1 4kFhBHp2NDdV+yslwWNr2qopdC1Y0u8VOzsSTcu6AR7W8Ryx20b2afRY1YtWnkthqVl0pA T2FE688Aj9UBsug6J/79IRifSaS6KzmT69jAjrC/YN0GFt3cA1P57mLreldylLuET+G/Sg BbglwcU8HcW0Y4Q/MTNSc11eaOQkKX+n4kI1K2BBPjeHm9Cg5O83GqWEaiIdFw== Authentication-Results: outgoing_mbo_mout; dkim=none; spf=pass (outgoing_mbo_mout: domain of hugo@hsal.es designates 2001:67c:2050:b231:465::1 as permitted sender) smtp.mailfrom=hugo@hsal.es Date: Tue, 3 Nov 2026 00:30:03 +0000 (WET) From: Hugo Sales To: Mario Limonciello , 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 Message-ID: <461302854.306462.1793665803972@app.mailbox.org> In-Reply-To: <7b87b864-7896-4260-aad6-a78687201c0f@kernel.org> References: <20261031134551.2735792-1-hugo@hsal.es> <7b87b864-7896-4260-aad6-a78687201c0f@kernel.org> Subject: Re: [PATCH] drm: panel-backlight-quirks: Add ASUS ROG Flow X13 3840x2400 panel 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 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Priority: 3 Importance: Normal X-Mailer: Open-Xchange Mailer v8.53.348 X-Originating-Client: open-xchange-appsuite X-Rspamd-Queue-Id: 4jJTx85RhZzMlSl On 11/2/26 23:13, Mario Limonciello wrote: > 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. Oh, damn, I didn't consider it could be damaging the panel and that it could be out of spec. I did try looking for a datasheet for the LQ134R1JW51 before sending this, but couldn't find one, and since it "worked" (the panel stays lit at requested brightness 0, which reads back as PWM 0 in amdgpu_current_backlight_pwm), I thought it was ok... I've asked two people at ASUS whether the panel spec allows a lower duty cycle, and I'll report back here. If you know someone who could be of help, I'd appreciate the suggestion One thing I noticed: 12 is also AMDGPU_DM_DEFAULT_MIN_BACKLIGHT, and it's what this machine's ATIF returned, as did the Framework's, for completely different panels. So the 12 ASUS returns for this Sharp panel looks like the AMD reference value passed through, not a number ASUS took from Sharp's datasheet. Do you or anyone else here know if that could be the case? Another data point is the VBT dumped from the BIOS of the ROG Flow Z13 2022 (GZ301ZE BIOS 321), which ships the LQ134R1JW52 (vs my LQ134R1JW51). It sets brightness_min_level to 0 and the older min_brightness field to 6, so i915 already lets that machine go down to PWM 0. This doesn't really settle anything for the JW51, though Assume the patch can be discarded unless I get a reply from ASUS, in which case I'll reply here again