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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 24BB5C369D1 for ; Fri, 25 Apr 2025 11:57:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:MIME-Version: References:In-Reply-To:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=eE54B0ulpkm+aWxhU2oeljTklX7QgI2Tl/j95Hz43BU=; b=kJuGccTpgZ06DnKnYDTXxwowzE XwGtrBd2aQcUDbu82f2LYo7XRc8b417W34CJpGwvgce4Hy6tswQ+qbIe1IkJ9TtIYll8i7JpccWCd TjxwKje6MomNL9Qw+WJMYO0j/Gf2SAI77jVv1KJv04aiNZmzXHZZIVaX51N76+F7DGxaxHnkgUQkI IUabKknWh0hnf6lP1hOspHO7Aj9IIzUYDtg3v5RBurBrLpXsZw/3I+PaX3M8sO/yEhrtKcqmrsCSW Aao6TFsc0ovJ5Th6nWgJrBK8MSrGFfzGqmuIYNCJc3Kxid09zG1Qdr4Y3EfIL7ukvl62DnJs+Anpt lWMLdqRw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1u8Hgj-0000000H2VX-1hGH; Fri, 25 Apr 2025 11:57:49 +0000 Received: from bali.collaboradmins.com ([148.251.105.195]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1u8G8n-0000000Ghl9-1YvA for linux-arm-kernel@lists.infradead.org; Fri, 25 Apr 2025 10:18:42 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1745576318; bh=+WMDRHwIxjNdFWZib1N8x93fRIjfmI7anWK8oxtytUg=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=fS8OBStgXmEHPXUtgkQM6i6oldyGjHhVXAffJrz40OrrJDixFwzubm2Jjg2v2cmUv LmnmNqmFur9E5HCtxdfibtsa36Vxyr+lqMpHBeDveVhs5fy0gzCs33TzLPPMof0iw4 ylrUroQH9zIEk5hXM3LaumCgjzrFtrshAOKLj5zW5YghhblY17lEoGLTUcdSfVYaV0 EXmuYNQYKhv0cRLgc+ntPLmiHduEjMltKTcEDNshKbQKBpkrggTkKwLq+n9vOLU3Ky C7Ad1vqexnj6rH7xkvQOSaU0XBCmXcaei5EN+/YyIst8AG3onO9rnByzIXpJuk8wc7 VmN2qkPkqiYTQ== Received: from eldfell (unknown [194.136.85.206]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (prime256v1) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: pq) by bali.collaboradmins.com (Postfix) with ESMTPSA id 4D41617E0F66; Fri, 25 Apr 2025 12:18:38 +0200 (CEST) Date: Fri, 25 Apr 2025 13:18:17 +0300 From: Pekka Paalanen To: Tomi Valkeinen Cc: Laurent Pinchart , Geert Uytterhoeven , Vishal Sagar , Anatoliy Klymenko , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Michal Simek , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Dmitry Baryshkov Subject: Re: [PATCH v4 03/11] drm/fourcc: Add DRM_FORMAT_Y8 Message-ID: <20250425131817.01b7f7d9@eldfell> In-Reply-To: References: <20250326-xilinx-formats-v4-0-322a300c6d72@ideasonboard.com> <20250326-xilinx-formats-v4-3-322a300c6d72@ideasonboard.com> <20250327112009.6b4dc430@eldfell> <20250327175842.130c0386@eldfell> <20250331105446.098f0fbe@eldfell> <20250331082135.GB13690@pendragon.ideasonboard.com> <20250331135337.61934003@eldfell> <20250401162732.731ef774@eldfell> <73bd6628-374d-417f-a30f-88a4b1d157bb@ideasonboard.com> <20250417111315.62a749e5@eldfell> X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: multipart/signed; boundary="Sig_/+HlgRhuvMGsiYHXtWjVBSQu"; protocol="application/pgp-signature"; micalg=pgp-sha256 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250425_031841_569044_7159CEBC X-CRM114-Status: GOOD ( 17.84 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org --Sig_/+HlgRhuvMGsiYHXtWjVBSQu Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Fri, 25 Apr 2025 11:38:28 +0300 Tomi Valkeinen wrote: > Hi Pekka, >=20 > On 17/04/2025 11:13, Pekka Paalanen wrote: > >> My understanding is that the Y-only pixel formats behave in a well > >> defined way (or, as well defined as the YUV formats), and there's > >> nothing more to add here. Is that right? =20 > >=20 > > There are two things: > >=20 > > - Y8 follows COLOR_RANGE property, just like all other YUV formats. > > - Y8 implies that Cb and Cr are both neutral (0.0 in nominal values). > >=20 > > I'd like these explicitly written down, so that they become obvious to > > everyone. I suspect either one might be easy to forget when writing > > code and taking shortcuts without thinking. =20 >=20 > I didn't find a suitable place in the docs for this, but would this, in=20 > the drm_fourcc.h, be enough: >=20 > /* > * Y-only (greyscale) formats > * > * The Y-only formats are handled similarly to the YCbCr formats in the= =20 > display > * pipeline, with the Cb and Cr implicitly neutral (0.0 in nominal=20 > values). This > * also means that COLOR_RANGE property applies to the Y-only formats. > * > */ >=20 > #define DRM_FORMAT_Y8 fourcc_code('G', 'R', 'E', 'Y') /* 8-bit Y-only */ > #define DRM_FORMAT_Y10_P32 fourcc_code('Y', 'P', 'A', '4') /* [31:0]=20 > x:Y2:Y1:Y0 2:10:10:10 little endian */ >=20 Hi Tomi, I would be very happy with that. 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