From patchwork Mon Jan 24 19:47:06 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 12722873 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 A81F4C433EF for ; Mon, 24 Jan 2022 19:47:16 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 6F4D010E6A6; Mon, 24 Jan 2022 19:47:15 +0000 (UTC) Received: from mail-ej1-x62d.google.com (mail-ej1-x62d.google.com [IPv6:2a00:1450:4864:20::62d]) by gabe.freedesktop.org (Postfix) with ESMTPS id 9345E10E6A6 for ; Mon, 24 Jan 2022 19:47:14 +0000 (UTC) Received: by mail-ej1-x62d.google.com with SMTP id d10so24448788eje.10 for ; Mon, 24 Jan 2022 11:47:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=lc7APd50YkFqw3zFombLtjhX0dQZ0+1XcIFSXUKBNWU=; b=UGrTFIWKpsKAjs683ggxdXs6/63ca0rixpRWQwB37TnpiyedBtuVGfEEMmNtTAxQQR 4TSsj2IwN8qhwv5OTGg0Qz+RXCb3LlN5hdUShnvKik8NbUcCCwxQbcxET9KU5rpCTeiR bLNNiTl6ud6y9ZXOufSy6ZbTB6puvwT3TBj1Y= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=lc7APd50YkFqw3zFombLtjhX0dQZ0+1XcIFSXUKBNWU=; b=5/S0M3eJMNN5F7LMI8r9qRX8EdPR6E8IR1niFRQg4Ocil96KJKD1exjIYrKSDIfUPP KulKSuPkHnobBat6U0bnditWHV/jorDGSfUFoRfQW+ZVLVlSOSrN1rtJGFGSUEkgrtcy fdAaWFbn5A8HGGeAgPJex17BB/q04hHyvCGjtEOVki8cZSUCL/iWHRqX+AqqlZ485EKw x8617yBm1gxlZm0gOjXagr8/8FPtVHUzXW/OYuEAcYRBPu7AQbcpY0RSx2fBrvUGe7FP YAUjl41ZXADsKCHGRVBUEH7w2NQtf6E0pu/oo75rv4NOiuoqUG0P8xY3bYAfsru5irrZ j/og== X-Gm-Message-State: AOAM533cBF66kLG1mpBOQI9B01gfAeUsPTzII116FXubIeLkfENYfR4E KbrsB0D6dMsKfYO08X8OwWq8HCllCQo3mw== X-Google-Smtp-Source: ABdhPJweOOHZRcrkFms49pe+uX75PVhPVRuaeBQyFEz7Np4o9riHmSH95zcal9Yoo3cIbQenXfovPQ== X-Received: by 2002:a17:907:97d6:: with SMTP id js22mr1642766ejc.527.1643053633080; Mon, 24 Jan 2022 11:47:13 -0800 (PST) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id d26sm7070334edy.92.2022.01.24.11.47.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 24 Jan 2022 11:47:12 -0800 (PST) From: Daniel Vetter To: DRI Development Subject: [PATCH] drm/docs: Document where the C8 color lut is stored Date: Mon, 24 Jan 2022 20:47:06 +0100 Message-Id: <20220124194706.930319-1-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.33.0 MIME-Version: 1.0 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: , Cc: David Airlie , Daniel Vetter , Geert Uytterhoeven , Thomas Zimmermann , Daniel Vetter Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Also add notes that for atomic drivers it's really somewhere else and no longer in struct drm_crtc. Maybe we should put a bigger warning here that this is confusing, since the pixel format is a plane property, but the GAMMA_LUT property is on the crtc. But I think we can fix this if/when someone finds a need for a per-plane CLUT, since I'm not sure such hw even exists. I'm also not sure whether even hardware with a CLUT and a full color correction pipeline with degamm/cgm/gamma exists. Motivated by comments from Geert that we have a gap here. Cc: Geert Uytterhoeven Cc: Ville Syrjälä Cc: Maarten Lankhorst Cc: Maxime Ripard Cc: Thomas Zimmermann Cc: David Airlie Cc: Daniel Vetter Signed-off-by: Daniel Vetter Reviewed-by: Laurent Pinchart --- drivers/gpu/drm/drm_color_mgmt.c | 4 ++++ include/drm/drm_crtc.h | 10 ++++++++++ 2 files changed, 14 insertions(+) diff --git a/drivers/gpu/drm/drm_color_mgmt.c b/drivers/gpu/drm/drm_color_mgmt.c index bb14f488c8f6..96ce57ad37e6 100644 --- a/drivers/gpu/drm/drm_color_mgmt.c +++ b/drivers/gpu/drm/drm_color_mgmt.c @@ -82,6 +82,10 @@ * driver boot-up state too. Drivers can access this blob through * &drm_crtc_state.gamma_lut. * + * Note that for mostly historical reasons stemming from Xorg heritage, + * this is also used to store the color lookup table (CLUT) for indexed + * formats like DRM_FORMAT_C8. + * * “GAMMA_LUT_SIZE”: * Unsigned range property to give the size of the lookup table to be set * on the GAMMA_LUT property (the size depends on the underlying hardware). diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h index 4d01b4d89775..03cc53220a2a 100644 --- a/include/drm/drm_crtc.h +++ b/include/drm/drm_crtc.h @@ -285,6 +285,10 @@ struct drm_crtc_state { * Lookup table for converting pixel data after the color conversion * matrix @ctm. See drm_crtc_enable_color_mgmt(). The blob (if not * NULL) is an array of &struct drm_color_lut. + * + * Note that for mostly historical reasons stemming from Xorg heritage, + * this is also used to store the color lookup table (CLUT) for indexed + * formats like DRM_FORMAT_C8. */ struct drm_property_blob *gamma_lut; @@ -1075,12 +1079,18 @@ struct drm_crtc { /** * @gamma_size: Size of legacy gamma ramp reported to userspace. Set up * by calling drm_mode_crtc_set_gamma_size(). + * + * Note that atomic drivers need to instead use + * &drm_crtc_state.gamma_lut. See drm_crtc_enable_color_mgmt(). */ uint32_t gamma_size; /** * @gamma_store: Gamma ramp values used by the legacy SETGAMMA and * GETGAMMA IOCTls. Set up by calling drm_mode_crtc_set_gamma_size(). + * + * Note that atomic drivers need to instead use + * &drm_crtc_state.gamma_lut. See drm_crtc_enable_color_mgmt(). */ uint16_t *gamma_store;