Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752625AbeAQJ1i (ORCPT + 1 other); Wed, 17 Jan 2018 04:27:38 -0500 Received: from bhuna.collabora.co.uk ([46.235.227.227]:37762 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752062AbeAQJ1g (ORCPT ); Wed, 17 Jan 2018 04:27:36 -0500 Subject: Re: [Nouveau] [PATCH] drm/nouveau/bar/gk20a: Avoid bar teardown during init To: Thierry Reding , Jon Hunter Cc: Ben Skeggs , David Airlie , nouveau@lists.freedesktop.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org References: <1515065349-10187-1-git-send-email-jonathanh@nvidia.com> <20180110122032.GA26614@ulmo> From: Guillaume Tucker Message-ID: Date: Wed, 17 Jan 2018 09:27:31 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.5.0 MIME-Version: 1.0 In-Reply-To: <20180110122032.GA26614@ulmo> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: On 10/01/18 12:20, Thierry Reding wrote: > On Thu, Jan 04, 2018 at 11:29:09AM +0000, Jon Hunter wrote: >> Commit bbb163e18960 ("drm/nouveau/bar: implement bar1 teardown") >> introduced add a teardown helper function for BAR1. During >> initialisation of the Nouveau, initially all the teardown helpers are >> called once, before calling their init counterparts. For gk20a, after >> the BAR1 teardown function is called, the device is hanging during the >> initialisation of the FB sub-device. At this point it is unclear why >> this is happening and this is still under investigation. However, this >> change is preventing Tegra124 devices from booting when Nouveau is >> enabled. To allow Tegra124 to boot, remove the teardown helper for >> gk20a. >> >> This is based upon a previous patch by Guillaume Tucker but limits >> the workaround to only gk20a GPUs. >> >> Fixes: bbb163e18960 ("drm/nouveau/bar: implement bar1 teardown") >> Reported-by: Guillaume Tucker >> Signed-off-by: Jon Hunter >> --- >> I am not happy that we do not yet fully understand the cause of >> the hang, but I am talking with a few people at NVIDIA about this >> and have a few things to look into. However, given that we are >> close to v4.15 being released and I am not sure we will have a >> proper fix in place before, I think it is best to workaround >> this for now. >> >> drivers/gpu/drm/nouveau/nvkm/subdev/bar/base.c | 3 ++- >> drivers/gpu/drm/nouveau/nvkm/subdev/bar/gk20a.c | 1 - >> 2 files changed, 2 insertions(+), 2 deletions(-) > > Acked-by: Thierry Reding Tested-by: Guillaume Tucker https://lava.collabora.co.uk/scheduler/job/1047172 Thanks for this workaround. Looking forward to having this platform back on track in mainline. I'm happy to run this boot test again with a proper fix in future patches, let me know if I can be of any help. Guillaume