From mboxrd@z Thu Jan  1 00:00:00 1970
From: Daniel Vetter <daniel@ffwll.ch>
Subject: Re: [PATCH 3/3] drm: do not sleep on vblank while holding a mutex
Date: Fri, 28 Oct 2011 16:51:49 +0200
Message-ID: <20111028145149.GC2919@phenom.ffwll.local>
References: <1319595614-9098-1-git-send-email-ihadzic@research.bell-labs.com>
	<1319595614-9098-4-git-send-email-ihadzic@research.bell-labs.com>
	<20111026075401.GD2889@phenom.ffwll.local>
	<Pine.GSO.4.62.1110261649120.15756@umail>
	<20111027104315.GA2927@phenom.ffwll.local>
	<Pine.GSO.4.62.1110272126130.19911@umail>
	<1319785144.7162.14.camel@thor.local>
	<20111028092032.GA2919@phenom.ffwll.local>
	<Pine.GSO.4.62.1110280703400.16410@umail>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Return-path: <dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org>
Received: from mail-wy0-f177.google.com (mail-wy0-f177.google.com
	[74.125.82.177])
	by gabe.freedesktop.org (Postfix) with ESMTP id D12529EBCF
	for <dri-devel@lists.freedesktop.org>;
	Fri, 28 Oct 2011 07:50:56 -0700 (PDT)
Received: by wyg8 with SMTP id 8so4937647wyg.36
	for <dri-devel@lists.freedesktop.org>;
	Fri, 28 Oct 2011 07:50:56 -0700 (PDT)
Content-Disposition: inline
In-Reply-To: <Pine.GSO.4.62.1110280703400.16410@umail>
List-Unsubscribe: <http://lists.freedesktop.org/mailman/options/dri-devel>,
	<mailto:dri-devel-request@lists.freedesktop.org?subject=unsubscribe>
List-Archive: <http://lists.freedesktop.org/archives/dri-devel>
List-Post: <mailto:dri-devel@lists.freedesktop.org>
List-Help: <mailto:dri-devel-request@lists.freedesktop.org?subject=help>
List-Subscribe: <http://lists.freedesktop.org/mailman/listinfo/dri-devel>,
	<mailto:dri-devel-request@lists.freedesktop.org?subject=subscribe>
Sender: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org
Errors-To: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org
To: Ilija Hadzic <ihadzic@research.bell-labs.com>
Cc: Michel =?iso-8859-1?Q?D=E4nzer?= <michel@daenzer.net>, dri-devel@lists.freedesktop.org
List-Id: dri-devel@lists.freedesktop.org

On Fri, Oct 28, 2011 at 07:10:51AM -0500, Ilija Hadzic wrote:
> I'll keep it then and figure out the best mutex/spinlock to use. It
> can be anything that exists on one-per-CRTC basis (vblank waits on
> different CTCs are not contending). The critical section is from
> that switch in which vblwait->request.sequence is incremented until
> it is assigned to dev->last_vblank_wait[crtc] (and we are only
> protecting that section against itself, executed in contexts of
> different PIDs).
> 
> I guess we settled now on this patch (other comments will be
> addressed in a different set of patches).

If you settle on keeping ->last_vblank_wait I think the easiest is to wrap
it with the dev->vbl_lock spinlock everywhere.
-Daniel
-- 
Daniel Vetter
Mail: daniel@ffwll.ch
Mobile: +41 (0)79 365 57 48