Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 4116D44236E; Mon, 17 Aug 2026 13:57:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786975058; cv=none; b=LRdUkQ5dY9QRoJn2PHBA7mc/Ve2+PdyuBkVgHomF77swzYzh1dfUjVkqb40gbxmdBxH8738bUgDvc+a+v6VvmwSHSBq2jsmuaccbWjCbp3rJOExpAcI3vkiismDd3MDXtC1+cwC6Qs/LyFg+NsbY5RosE0BIckBjoYvRzNrNLoU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786975058; c=relaxed/simple; bh=S1X2v0Gv6PKDvbIbUlHCKlpk+z43PrWOQQsqZAhkOXg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=po7RuFNWX5QGpjp8f6UY9qqS/kM78HWK6kDvQCTCQnVgE5cGKT9E+TLNR/I47TntyetgQEFMa5B/d6mgm1pl/J4c3HOd5BAZzK3REm8Ms9qkiKSz2lXuhRyVp5HlnNxUWGgP8hQXn6zBZZemuP/4tsYD6pcvg8Jd2srQZZPmOQU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=W9ynaEFT; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="W9ynaEFT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8BDA51F000E9; Mon, 17 Aug 2026 13:57:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786975056; bh=4WgW1Pbie6ej6DN/hgZFE6anjGEXf2YAdpc3Ov3rguI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=W9ynaEFTCcc9mw2zv7jCPVEH/4qWFpAzJwGMjny5P+44a0/hKfnZB//D86WKh2+Pt fB4BSgGydHvo9OINXVulBiagtvjJTBRIAiaGlZ7OY1w8mIB2Q06GcZ2u7fWrdE2ezd WyQxubv8y5umIpGNkLUAirsmNr4YZqvs7RrWBY8A= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Alex Deucher , Thorsten Leemhuis , Sergio Callegari , Mario Limonciello , Sasha Levin Subject: [PATCH 6.18 146/250] Revert "drm/amd/display: Fix backlight max_brightness to match exported range" Date: Mon, 17 Aug 2026 15:31:47 +0200 Message-ID: <20260817132542.519104730@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260817132536.466235697@linuxfoundation.org> References: <20260817132536.466235697@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alex Deucher This reverts commit 490ceacd2162de919a142bcb4eff363bb493b1de. This patch is apparently missing a dependency from 7.2 as users have not reported any regressions with 7.2-rc, but there are regressions on 6.18. The regression manifests as inconsistent lower brightness at the top end (e.g., around 98%). Closes: https://gitlab.freedesktop.org/drm/amd/-/work_items/5562 Signed-off-by: Alex Deucher Cc: Thorsten Leemhuis Cc: Sergio Callegari Cc: Mario Limonciello Signed-off-by: Sasha Levin --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index 4f53297786623..fd5a6c6532a1e 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -5222,11 +5222,11 @@ amdgpu_dm_register_backlight_device(struct amdgpu_dm_connector *aconnector) caps = &dm->backlight_caps[aconnector->bl_idx]; if (get_brightness_range(caps, &min, &max)) { if (power_supply_is_system_supplied() > 0) - props.brightness = DIV_ROUND_CLOSEST(max * caps->ac_level, 100); + props.brightness = DIV_ROUND_CLOSEST((max - min) * caps->ac_level, 100); else - props.brightness = DIV_ROUND_CLOSEST(max * caps->dc_level, 100); + props.brightness = DIV_ROUND_CLOSEST((max - min) * caps->dc_level, 100); /* min is zero, so max needs to be adjusted */ - props.max_brightness = max; + props.max_brightness = max - min; drm_dbg(drm, "Backlight caps: min: %d, max: %d, ac %d, dc %d\n", min, max, caps->ac_level, caps->dc_level); } else -- 2.53.0