From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Vetter Subject: Re: [Intel-gfx] [PATCH] drm/i915: don't update the dri1 breadcrumb with modesetting Date: Tue, 10 Dec 2013 14:48:23 +0100 Message-ID: <20131210134823.GI9804@phenom.ffwll.local> References: <1386678241-18228-1-git-send-email-daniel.vetter@ffwll.ch> <20131210124412.GE10793@nuc-i3427.alporthouse.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20131210124412.GE10793@nuc-i3427.alporthouse.com> Sender: stable-owner@vger.kernel.org To: Chris Wilson , Daniel Vetter , Intel Graphics Development , Eugene Shatokhin , stable@vger.kernel.org List-Id: intel-gfx@lists.freedesktop.org On Tue, Dec 10, 2013 at 12:44:12PM +0000, Chris Wilson wrote: > On Tue, Dec 10, 2013 at 01:24:01PM +0100, Daniel Vetter wrote: > > The update is horribly racy since it doesn't protect at all against > > concurrent closing of the master fd. And it can't really since that > > requires us to grab a mutex. > > > > Instead of jumping through hoops and offloading this to a worker > > thread just block this bit of code for the modesetting driver. > > > > Reported-by: Eugene Shatokhin > > Cc: Eugene Shatokhin > > Cc: stable@vger.kernel.org > > Signed-off-by: Daniel Vetter > > We should also not be calling update_dri1_breadcrumb unless we have a > USER_INTERRUPT. The other updates to the breadcrumb hws index do not > appear to be serialised by anything other than polling. Well, this is what's been there before and I don't really want to touch dri1/ums code at all. So I think we'll just keep this here until we'll all put it on the big pyre ;-) -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch