Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754430AbcK1HOS (ORCPT ); Mon, 28 Nov 2016 02:14:18 -0500 Received: from mail.netline.ch ([148.251.143.178]:34172 "EHLO netline-mail3.netline.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754353AbcK1HOK (ORCPT ); Mon, 28 Nov 2016 02:14:10 -0500 Subject: Re: drm: GPF in drm_getcap To: Daniel Vetter , David Herrmann References: Cc: Dmitry Vyukov , syzkaller , David Airlie , "dri-devel@lists.freedesktop.org" , LKML From: =?UTF-8?Q?Michel_D=c3=a4nzer?= Message-ID: <03fd1a91-fe9e-917d-72fb-a763c4e8179d@daenzer.net> Date: Mon, 28 Nov 2016 16:14:01 +0900 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Icedove/45.5.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1767 Lines: 48 On 28/11/16 03:55 PM, Daniel Vetter wrote: > On Sat, Nov 26, 2016 at 7:22 PM, David Herrmann wrote: >> On Sat, Nov 26, 2016 at 7:07 PM, Dmitry Vyukov wrote: >>> grep "card0" dmesg: >>> [ 5.298617] device: 'card0': device_add >>> [ 5.298946] PM: Adding info for No Bus:card0 >>> [ 6.436178] device: 'card0': device_add >>> [ 6.436488] PM: Adding info for No Bus:card0 >>> >>> >>> # ls -l /dev/dri/card0 >>> crw-rw---T 1 root video 226, 0 Nov 26 18:05 /dev/dri/card0 >>> >>> # ls -lt /sys/class/drm/card0/device/ >>> ls: cannot access /sys/class/drm/card0/device/: No such file or directory >>> >>> # ls -lt /sys/class/drm/card0/device/driver >>> ls: cannot access /sys/class/drm/card0/device/driver: No such file or directory >> >> Looks like vgem. Something like this should help: >> >> https://gist.github.com/dvdhrm/1bcdf4f3485aa1614a0198a7b90515e2 >> >> I wonder whether it would be more appropriate to return -ENOTSUPP rather than 0. Can't see how that would matter FWIW. > Seems a bit overkill, but can't hurt. This is most likely a > regression, probably introduced in > > commit f837297ad82480024d3ad08cd84f6670bcafa862 > Author: Michel Dänzer > Date: Mon Aug 8 16:23:39 2016 +0900 > > drm: Add DRM_MODE_PAGE_FLIP_TARGET_ABSOLUTE/RELATIVE flags v2 > > Michel, can you pls take care of this? Either with a minimal fix, or > by adopting David's patch? Can't we just use David's patch as-is? If not, I think Dmitry or someone else would be better equipped than me to extract a minimal fix from it and test it. -- Earthling Michel Dänzer | http://www.amd.com Libre software enthusiast | Mesa and X developer