From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 93D2DC624DE for ; Thu, 3 Sep 2026 07:34:19 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D9CBB10F413; Thu, 3 Sep 2026 07:33:57 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="n0OhP2ju"; dkim-atps=neutral Received: from mail-pl1-f170.google.com (mail-pl1-f170.google.com [209.85.214.170]) by gabe.freedesktop.org (Postfix) with ESMTPS id E642B10E3F7 for ; Tue, 1 Sep 2026 14:02:21 +0000 (UTC) Received: by mail-pl1-f170.google.com with SMTP id d9443c01a7336-2d91518a63fso8141765ad.0 for ; Tue, 01 Sep 2026 07:02:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1788271341; x=1788876141; darn=lists.freedesktop.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to:content-type; bh=RJiqhKlCrTwwf/cJleA2B3ljUR61iwycQECqOoNxMUo=; b=n0OhP2juX8oBzc8xrDsXhemIeUr1quc92J1iGox54uRQ8edIOwHTbh8jNOaGWsCpUh DVEzhDruDwa3Vn8df0HdHH6vzMNDKpP3KxN9oeKbhxwFkryUY95N4Nvdge/Byg8yIVf6 F+cnvcV1VMXhCqXrrBNZfknK1GlmzBFHSQrP3Qsi+aiQdLYFe7RJmfywvFG2+eonyu7I s49mMyQ2qbuh2AXUc53VdWriBfmy3KIwcY4GD5hqjjdrmt1Ct+VwEweipzOo7U3S7EcS cs6iYUgOaRCAiYBfM/9IgixPMvqQgwPWIooc+i4Mmpgex4RUAEe6xv8g0TXgwUoCM2Ki G6Kg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788271341; x=1788876141; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=RJiqhKlCrTwwf/cJleA2B3ljUR61iwycQECqOoNxMUo=; b=QGCzJjTMaUVaH2J3+/1m8lN2r+UOO+fNinDy8rtrdkPjJyQqPOBmATrEZreLhK0pjs TcEyFCg9CZsKvug5yd39xCO25TXalQUE3gshMrKz0p0wVxKb9ufDqJ8Q0rEUkifJ/PsC hrBC4OZvaTy1cEabAnu+1BUEGA7lSBRTnDXiLD/02kARE0MNkmr2tRdPfA926YobZmzz OF7k9cdDr9Lbky+6M66H5YAoeDCVQUx6zrBQsoEaMYP4sOcFcORHF4D7wDylvHzP5RSl qz4fTSEuWnRM4B4EUpfxrbONOjJF6FonwKl6WuQMwDTOhbgpAi4fQeNLKmYqQQUX5AUK xneg== X-Gm-Message-State: AFuF++kPaLdhvUDWGAx+oQ1SrOFyZWXnIBZOEAFQKTGVcZvYbvT02ooV Rl79MaD14QmSimPHuo0/CTchz3QfJpbLlo13U2eDU6CoQorz2l255paK X-Gm-Gg: AYBFou1eouM/LyipnIP4bsGRgSPK5H3PTgOcnmwVcB3L2GoBVZ9Mf7wn3dgGOM8csjZ ECRWMT+4uZpGAhU+6EOtGKe9vtNLni9EMrJ5jSIqljl8h3PSve/WKeB1Q84EJEEPyvbS6MYSOI3 tzJq3aREu7z5/3bX4A9/Rvupr4ouj4UIVd+UxwPrdRP5/Ydf5G0d7yffWtWYyb7nEP3LCspaZGB N0tqpiffnz6r67l7KL3nwjhaxh2/CZ/70ZqtJMOPj72ouhts2ol7HKJyKFt0uhZ5PaWRC1wt0BC VlHQYqDpTK+eW1zOYqIOVhmg/mSDaNJd2yhcHcYbeBBlIXlP0axCtZMcRraOFygcqYZNBzKDWV3 3394ySQ8lHkc9WNrXrH3JcN72DmbpoaoEKxSvO/q+1OfMPfwHraq0+8ohGloZOQWB6rXf0U81UG pRUzr1wjDTYU8KYYTrADJ2KSA3o8/+YbwHWNy4NtjCd99Aiz8VzVCHgrkvUw== X-Received: by 2002:a17:903:2b07:b0:2d8:d4de:fa80 with SMTP id d9443c01a7336-2d8d4defec6mr398333105ad.4.1788271341199; Tue, 01 Sep 2026 07:02:21 -0700 (PDT) Received: from loontop ([163.61.5.136]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2d7594fc0b3sm53833895ad.16.2026.09.01.07.02.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 01 Sep 2026 07:02:15 -0700 (PDT) From: Aarav Kumar To: amd-gfx@lists.freedesktop.org Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, harry.wentland@amd.com, sunpeng.li@amd.com, siqueira@igalia.com, alexander.deucher@amd.com, christian.koenig@amd.com, ray.wu@amd.com, Aarav Kumar Subject: [PATCH] drm/amd/display: use linear backlight curve on Linux Date: Tue, 1 Sep 2026 19:31:55 +0530 Message-ID: <20260901140155.19129-1-aarav.240604@gmail.com> X-Mailer: git-send-email 2.55.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Mailman-Approved-At: Thu, 03 Sep 2026 07:33:13 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" The power module currently uses a non-linear backlight curve for the Linux backlight path. This results in incorrect brightness levels on affected systems. Use the linear backlight curve instead to preserve the existing brightness-to-PWM mapping. Tested on an AMD laptop with an eDP panel. The regression was reproduced with commit 3c108046e1d6 ("drm/amd/display: Add power module on Linux"), and the brightness behavior was restored with this change. Fixes: 3c108046e1d6 ("drm/amd/display: Add power module on Linux") Link: https://gitlab.freedesktop.org/drm/amd/-/work_items/5723 Signed-off-by: Aarav Kumar --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) 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 8d690468d..cd10a5d45 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -1913,7 +1913,7 @@ static int amdgpu_dm_init_power_module(struct amdgpu_display_manager *dm) !(amdgpu_dc_feature_mask & DC_DISABLE_FRACTIONAL_PWM_MASK); init_data[i].use_custom_backlight_caps = false; init_data[i].custom_backlight_caps_config_no = 0; - init_data[i].use_linear_backlight_curve = false; + init_data[i].use_linear_backlight_curve = true; init_data[i].def_varibright_enable = 0; init_data[i].varibright_level = 0; /* -- 2.55.0