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 18D27ECAAD3 for ; Wed, 14 Sep 2022 14:58:54 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id BB5F810E0B6; Wed, 14 Sep 2022 14:58:52 +0000 (UTC) Received: from out20-38.mail.aliyun.com (out20-38.mail.aliyun.com [115.124.20.38]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2025C10E0B6 for ; Wed, 14 Sep 2022 14:58:47 +0000 (UTC) X-Alimail-AntiSpam: AC=CONTINUE; BC=0.04440973|-1; CH=green; DM=|CONTINUE|false|; DS=CONTINUE|ham_regular_dialog|0.355538-0.0192772-0.625185; FP=0|0|0|0|0|-1|-1|-1; HT=ay29a033018047204; MF=wangyugui@e16-tech.com; NM=1; PH=DS; RN=3; RT=3; SR=0; TI=SMTPD_---.PFYDXuf_1663167483; Received: from 192.168.2.112(mailfrom:wangyugui@e16-tech.com fp:SMTPD_---.PFYDXuf_1663167483) by smtp.aliyun-inc.com; Wed, 14 Sep 2022 22:58:03 +0800 Date: Wed, 14 Sep 2022 22:58:11 +0800 From: Wang Yugui To: Thomas Zimmermann Subject: Re: mgag200 broken on kernel-6.0-rc3 on DELL/T620 In-Reply-To: <03f80477-78c1-2ef3-40bf-58f8c9daa1c8@suse.de> References: <20220914162920.7233.409509F4@e16-tech.com> <03f80477-78c1-2ef3-40bf-58f8c9daa1c8@suse.de> Message-Id: <20220914225809.763F.409509F4@e16-tech.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.75.04 [en] 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: Jocelyn Falempe , dri-devel Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Hi, > (cc: Jocelyn) > > Hi > > Am 14.09.22 um 10:29 schrieb Wang Yugui: > > Hi, > > > > > >> Hi > >> > >> Am 13.09.22 um 17:15 schrieb Wang Yugui: > >> [...] > >>>>> > >>>>> so I tried to revert patch of mgag200 driver in batch of 2 or 3, the I > >>>>> noticed the patch 'Subject: drm/mgag200: Remove special case for G200SE > >>>>> with <2 MiB' and then tried this dirty fix. > >>>> > >>>> Oh, great work! Thank you. From looking at the screenshot that you provided, it seems as if the 24-bit mode setting is broken. I'm not sure why the G200SE workaround applies to a G200ER, but we'll see. > >>> > >>> I tested 'preferred_depth = 32' too. it works on T630 too. > >>> > >>> so both 16 and 32 work, but 24 failed on DELL/T630. > >> > >> I tried on my test machine with a 5.19 kernel and found that 32-bit and 24-bit pixels work, but 16-bit looks incorrect. > >> > >> What are the results if you boot your kernel 5.19.3 with the parameter video=1024x768-24? This should enable 24-bit pixels. > >> > >> How does video=1024x768-16 look with the 5.19 kernel? > > > > test result here > > kernel 5.19.3 & video=1024x768-24 > > dell/T620/centos-8.5 broken > > dell/T630/centos-7.9 broken > > I assume that Centos 7 and 8 have fairly old kernels? So it's been a long-standing bug. We install kernel 5.19.3/5.15.67 into Centos 7 and 8. default it work well. broken just when 'video=1024x768-24', so it may not a long-standing bug. > 24-bit works on my G200HE and G200 test machines. Maybe the G200ER has a bug. > > When I try 16-bit depth, the display works, but is way too dark. No fiddling with the LUT tables fixes this. It's 90s hardware, so it should support 16-bit framebuffers well, but there's no obvious bug to be seen. > > I guess, we could remove 16 and 24 bit support for now if nothing else helps. maybe better if we revert 73f54d5d9682 (drm/mgag200: Remove special case for G200SE with <2 MiB) because there is no test result on device G200_SE static unsigned int mgag200_preferred_depth(struct mga_device *mdev) { if (IS_G200_SE(mdev) && mdev->vram_fb_available < (2048*1024)) return 16; else return 32; } Best Regards Wang Yugui (wangyugui@e16-tech.com) 2022/09/14