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 20E34C02183 for ; Thu, 16 Jan 2025 08:44:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=UtGjlo9b7or5xS/AZWr6wC9Qe5aGlcx9KBLSU4xgE4E=; b=kiBaB+yHE/GUdq hXmm8FWx+TfMdFWFnoAuCgg8J81K+GIRc8+6u2FWslMGq6IOUb7n281HilXsfcH8YuMGHvGQGRupE KscVvayRt/smskBt2RcFtIEGvItnFZ1vGpy4iwxw/mjJNBLudqoRtFc3dVWNfa/Yr8qazRSzPFFqz wfweO7GfT8pYTABoxXlEXVrlseQjJQZPCguX9pjyc1dV6kptRuRggTo2K4lPC7tsUU9JNy4aLaaUT cGBbHBayEh6HrEHs2Gla1xqIO1qipHoSj0oDUDVx9GXOPKWMsETHM2/RChSHphnsYyG1Lc8R4N5j2 KGcOZtdslAHVJCy9iRWQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tYLTk-0000000EFtj-3uWW; Thu, 16 Jan 2025 08:43:52 +0000 Received: from perceval.ideasonboard.com ([213.167.242.64]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tYLTh-0000000EFsC-3qaU; Thu, 16 Jan 2025 08:43:51 +0000 Received: from pendragon.ideasonboard.com (unknown [193.209.96.36]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 1CDD7169; Thu, 16 Jan 2025 09:42:47 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1737016967; bh=YBJYqGqQ2U3g/glMhqBtVA7c9PNcNKm2bF2hwWN3X/8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=LEeZiJfRiaftp5JL3OuhSGJ31fbSk67YMrTfIULuryGPguJN8dhwOq+oPh23KD4oZ oDgG9Q7qiklC025s5e31jn5W8DZrWY3XLnKdac3TlZaKlReDu0jJF+McdlL4rZbfey vio2zbz4p7HYes9E+SH0Bj1kP+VRYA2cki8/bjIo= Date: Thu, 16 Jan 2025 10:43:40 +0200 From: Laurent Pinchart To: Daniel Stone Cc: Tomi Valkeinen , Thomas Zimmermann , maarten.lankhorst@linux.intel.com, mripard@kernel.org, airlied@gmail.com, simona@ffwll.ch, dri-devel@lists.freedesktop.org, linux-mediatek@lists.infradead.org, freedreno@lists.freedesktop.org, linux-arm-msm@vger.kernel.org, imx@lists.linux.dev, linux-samsung-soc@vger.kernel.org, nouveau@lists.freedesktop.org, virtualization@lists.linux.dev, spice-devel@lists.freedesktop.org, linux-renesas-soc@vger.kernel.org, linux-rockchip@lists.infradead.org, linux-tegra@vger.kernel.org, intel-xe@lists.freedesktop.org, xen-devel@lists.xenproject.org, Andy Yan Subject: Re: [PATCH v2 25/25] drm/xlnx: Compute dumb-buffer sizes with drm_mode_size_dumb() Message-ID: <20250116084340.GF6754@pendragon.ideasonboard.com> References: <0ea6be58-0e04-4172-87cd-064a3e4a43bc@suse.de> <4af0b6a7-c16a-4187-bbf5-365a9c86de21@suse.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250116_004350_089376_5543D6E2 X-CRM114-Status: GOOD ( 20.29 ) X-BeenThere: linux-rockchip@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Upstream kernel work for Rockchip platforms List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-rockchip" Errors-To: linux-rockchip-bounces+linux-rockchip=archiver.kernel.org@lists.infradead.org On Wed, Jan 15, 2025 at 02:34:26PM +0000, Daniel Stone wrote: > On Wed, 15 Jan 2025 at 14:20, Tomi Valkeinen wrote: > > No disagreement there, we need CREATE_DUMB2. > > > > My point is that we have the current UAPI, and we have userspace using > > it, but we don't have clear rules what the ioctl does with specific > > parameters, and we don't document how it has to be used. > > > > Perhaps the situation is bad, and all we can really say is that > > CREATE_DUMB only works for use with simple RGB formats, and the behavior > > for all other formats is platform specific. But I think even that would > > be valuable in the UAPI docs. > > Yeah, CREATE_DUMB only works for use with simple RGB formats in a > linear layout. Not monochrome or YUV or tiled or displayed rotated or > whatever. > > If it happens to accidentally work for other uses, that's fine, but > it's not generically reliable for anything other than simple linear > RGB. It's intended to let you do splash screens, consoles, recovery > password entries, and software-rendered compositors if you really > want. Anything more than that isn't 'dumb'. We have lots of software out there that rely on CREATE_DUMB supporting YUV linear formats, and lots of drivers (mostly on Arm I suppose) that implement YUV support in CREATE_DUMB. I'm fine replacing it with something better, but I think we need a standard ioctl that can create linear YUV buffers. I've been told many times that DRM doesn't want to standardize buffer allocation further than what CREATE_DUMB is made for. Can we reconsider this rule then ? -- Regards, Laurent Pinchart _______________________________________________ Linux-rockchip mailing list Linux-rockchip@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-rockchip