From nobody Mon Feb 9 23:04:10 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E1A01C04E69 for ; Thu, 10 Aug 2023 16:04:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236552AbjHJQEg (ORCPT ); Thu, 10 Aug 2023 12:04:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54878 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236334AbjHJQEA (ORCPT ); Thu, 10 Aug 2023 12:04:00 -0400 Received: from fanzine2.igalia.com (fanzine2.igalia.com [213.97.179.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 799532705 for ; Thu, 10 Aug 2023 09:03:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=jHZ39nOiWNLuUcZxnNLJc24b5oV7xLgRtpwx3i1dlkA=; b=sVX+iW8VoXBFM+HvUD/I2W3aqB erwTXAFPg/RCab1XT3IxUXsEcVpXDOC345wdys+buPFSM5OjPQBBSvXE7JsbKT4+58EgyOeMWHSZ9 w2leZZivtA1WhnV6QmxE9fcZH1jumVUOvj899ZsJQo6yv3jHo01KnAf0EdQ9awX6AJzFfuv4ps1eK GqzNFJ5yYbFMFgrq/G+s79csLWgfIrzKt2IBd1OCwu2aEyxY5eZa8fus6jk6IAgO5Az6gdKOdJg6F XWPlqKX6LHNYqI4UNYBCCakvwgTxhJFYpH3psczxQZWxFI0Q9v3k54N3mAd7+a9yVJzzgegAJK8iT M1k9nbUA==; Received: from [38.44.68.151] (helo=killbill.home) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim) id 1qU88a-00GjYD-GP; Thu, 10 Aug 2023 18:03:48 +0200 From: Melissa Wen To: amd-gfx@lists.freedesktop.org, Harry Wentland , Rodrigo Siqueira , sunpeng.li@amd.com, Alex Deucher , dri-devel@lists.freedesktop.org, christian.koenig@amd.com, Xinhui.Pan@amd.com, airlied@gmail.com, daniel@ffwll.ch Cc: Joshua Ashton , Sebastian Wick , Xaver Hugl , Shashank Sharma , Nicholas Kazlauskas , sungjoon.kim@amd.com, Alex Hung , Pekka Paalanen , Simon Ser , kernel-dev@igalia.com, linux-kernel@vger.kernel.org Subject: [PATCH v2 14/34] drm/amd/display: add comments to describe DM crtc color mgmt behavior Date: Thu, 10 Aug 2023 15:02:54 -0100 Message-Id: <20230810160314.48225-15-mwen@igalia.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230810160314.48225-1-mwen@igalia.com> References: <20230810160314.48225-1-mwen@igalia.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Describe some expected behavior of the AMD DM color mgmt programming. Signed-off-by: Melissa Wen --- .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c b/driv= ers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c index 841e0391f7fb..0a9aa162d4a0 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c @@ -640,12 +640,23 @@ int amdgpu_dm_update_crtc_color_mgmt(struct dm_crtc_s= tate *crtc) stream->out_transfer_func->type =3D TF_TYPE_DISTRIBUTED_POINTS; stream->out_transfer_func->tf =3D TRANSFER_FUNCTION_SRGB; =20 + /* Note: although we pass has_rom as parameter here, we never + * actually use ROM because the color module only takes the ROM + * path if transfer_func->type =3D=3D PREDEFINED. + * + * See more in mod_color_calculate_regamma_params() + */ r =3D __set_legacy_tf(stream->out_transfer_func, regamma_lut, regamma_size, has_rom); if (r) return r; } else if (has_regamma) { - /* If atomic regamma, CRTC RGM goes into RGM LUT. */ + /* CRTC RGM goes into RGM LUT. + * + * Note: there is no implicit sRGB regamma here. We are using + * degamma calculation from color module to calculate the curve + * from a linear base. + */ stream->out_transfer_func->type =3D TF_TYPE_DISTRIBUTED_POINTS; stream->out_transfer_func->tf =3D TRANSFER_FUNCTION_LINEAR; =20 --=20 2.40.1