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 9E667C00140 for ; Mon, 8 Aug 2022 13:28:05 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 1AA8B98F5E; Mon, 8 Aug 2022 13:25:56 +0000 (UTC) Received: from smtp.domeneshop.no (smtp.domeneshop.no [IPv6:2a01:5b40:0:3005::1]) by gabe.freedesktop.org (Postfix) with ESMTPS id 5F4CE9A4F0 for ; Mon, 8 Aug 2022 13:03:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=tronnes.org ; s=ds202112; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:From: References:Cc:To:Subject:MIME-Version:Date:Message-ID:Sender:Reply-To: 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; 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charset=UTF-8 Content-Transfer-Encoding: 7bit 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: Dom Cobley , Dave Stevenson , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Mateusz Kwiatkowski , =?UTF-8?Q?Noralf_Tr=c3=b8nnes?= , Geert Uytterhoeven , linux-amlogic@lists.infradead.org, linux-sunxi@lists.linux.dev, Phil Elwell , linux-arm-kernel@lists.infradead.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Den 29.07.2022 18.34, skrev Maxime Ripard: > Hi, > > Here's a series aiming at improving the command line named modes support, > and more importantly how we deal with all the analog TV variants. > > The named modes support were initially introduced to allow to specify the > analog TV mode to be used. > > However, this was causing multiple issues: > > * The mode name parsed on the command line was passed directly to the > driver, which had to figure out which mode it was suppose to match; > > * Figuring that out wasn't really easy, since the video= argument or what > the userspace might not even have a name in the first place, but > instead could have passed a mode with the same timings; > > * The fallback to matching on the timings was mostly working as long as > we were supporting one 525 lines (most likely NSTC) and one 625 lines > (PAL), but couldn't differentiate between two modes with the same > timings (NTSC vs PAL-M vs NSTC-J for example); > > * There was also some overlap with the tv mode property registered by > drm_mode_create_tv_properties(), but named modes weren't interacting > with that property at all. > > * Even though that property was generic, its possible values were > specific to each drivers, which made some generic support difficult. > > Thus, I chose to tackle in multiple steps: > > * A new TV norm property was introduced, with generic values, each driver > reporting through a bitmask what standard it supports to the userspace; > > * This option was added to the command line parsing code to be able to > specify it on the kernel command line, and new atomic_check and reset > helpers were created to integrate properly into atomic KMS; > > * The named mode parsing code is now creating a proper display mode for > the given named mode, and the TV standard will thus be part of the > connector state; > > * Two drivers were converted and tested for now (vc4 and sun4i), with > some backward compatibility code to translate the old TV mode to the > new TV mode; > > Unit tests were created along the way. Nouveau, ch7006 and gud are > currently broken for now since I expect that work to be reworked fairly > significantly. I'm also not entirely sure about how to migrate GUD to the > new property. > I have looked at gud and I think the future proof solution is to add a new TV_NORM property to the GUD protocol and add backwards compatibility for the GUD_TV_MODE property (just for the modes that Raspberry Pi supports since the gadget driver is out of tree). I don't bother supporting the tv.mode property in userspace (I haven't seen anything that uses the property). I have written up most of the host driver changes but I have to do the gadget side as well to make sure it works. I'll post some patches when I'm done. In hindsight I should have used a bitmask for the TV standards in the first place ;) Noralf.