From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754346AbcE3Imj (ORCPT ); Mon, 30 May 2016 04:42:39 -0400 Received: from mail-wm0-f66.google.com ([74.125.82.66]:33623 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754035AbcE3Imi (ORCPT ); Mon, 30 May 2016 04:42:38 -0400 Date: Mon, 30 May 2016 10:42:33 +0200 From: Daniel Vetter To: Gerd Hoffmann , dri-devel , open list , "open list:VIRTIO GPU DRIVER" Subject: Re: [PATCH v3 7/7] [wip] virtio-gpu: add page flip support Message-ID: <20160530084233.GA27098@phenom.ffwll.local> Mail-Followup-To: Gerd Hoffmann , dri-devel , open list , "open list:VIRTIO GPU DRIVER" References: <1443787104-24243-1-git-send-email-kraxel@redhat.com> <1443787104-24243-8-git-send-email-kraxel@redhat.com> <1464335163.10663.7.camel@redhat.com> <20160527075027.GW27098@phenom.ffwll.local> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160527075027.GW27098@phenom.ffwll.local> X-Operating-System: Linux phenom 4.6.0-rc5+ User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 27, 2016 at 09:50:27AM +0200, Daniel Vetter wrote: > On Fri, May 27, 2016 at 09:46:03AM +0200, Gerd Hoffmann wrote: > > On Mi, 2016-05-25 at 18:37 +0200, Daniel Vetter wrote: > > > On Fri, Oct 2, 2015 at 1:58 PM, Gerd Hoffmann wrote: > > > > Signed-off-by: Gerd Hoffmann > > > > > > So I entirely missed this, but this isn't really how to implement > > > page_flip for an atomic driver. Working on some stuff and will hack up > > > a likely totally broken patch, but should be enough as guideline. > > > -Daniel > > > > Hmm, no patch in my inbox yet. Care to send it over or give some hints > > what is wrong with this? > > You should use drm_atomic_helper_page_flip as .page_flip hook instead of > rolling your own, when you have a brand-new atomic driver. If that helper > doesn't work that means you have a bug in your driver somewhere. > > And indeed virtio just plugs in drm_atomic_helper_commit, which thus far > doesnt' do nonblocking commits, which means the page flip stuff won't > work. I'm working on generic nonblocking atomic to fix this up. Currently > still wip and buggy though, hence no patches. > > But I'll take you up on the implied offer to help out and test ;-) Ok, patches are now on the list and also in my fdo repo at: https://cgit.freedesktop.org/~danvet/drm/log/ git://people.freedesktop.org/~danvet/drm stuff Would be really awesome if you could test this on virtio. Note that the new nonblocking helpers require that your atomic backend gets the drm event handling right. So if there's a bug in that logic then you'll see lots of dmesg noise about waits timing out (after 10s of waiting). From a quick inspection it should work though. Upshot is that once you get normal modeset to work with those new helpers, then nonblocking should Just Work, and there's no need anymore for additional testing. Or at least shouldn't. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch