From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Vetter Subject: Re: [PATCH] drm/i915: paper over missed irq issues with force wake vodoo Date: Sat, 14 Jan 2012 00:55:22 +0100 Message-ID: <20120113235522.GF3843@phenom.ffwll.local> References: <1325702445-2231-1-git-send-email-daniel.vetter@ffwll.ch> <86lipb367b.fsf@sumi.keithp.com> <20120113235231.GE3843@phenom.ffwll.local> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-ww0-f43.google.com (mail-ww0-f43.google.com [74.125.82.43]) by gabe.freedesktop.org (Postfix) with ESMTP id 745879EF70 for ; Fri, 13 Jan 2012 15:53:16 -0800 (PST) Received: by wgbdt11 with SMTP id dt11so3479766wgb.12 for ; Fri, 13 Jan 2012 15:53:15 -0800 (PST) Content-Disposition: inline In-Reply-To: <20120113235231.GE3843@phenom.ffwll.local> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org Errors-To: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org To: Keith Packard Cc: Daniel Vetter , intel-gfx , Eugeni Dodonov , stable@kernel.org List-Id: intel-gfx@lists.freedesktop.org On Sat, Jan 14, 2012 at 12:52:31AM +0100, Daniel Vetter wrote: > On Fri, Jan 13, 2012 at 08:42:00AM -0800, Keith Packard wrote: > > On Wed, 4 Jan 2012 19:40:45 +0100, Daniel Vetter wrote: > > > > > Two things seem to do the trick on my ivb machine here: > > > - prevent the gt from powering down while waiting for seqno > > > notification interrupts by grabbing the force_wake in get_irq (and > > > dropping it in put_irq again). > > > - ordering writes from the ring's CS by reading a CS register, ACTHD > > > seems to work. > > > > I've rebased this code on top of drm-intel-fixes and pushed it to my > > forcewake-spinlock branch. I'd like to get this pushed to > > drm-intel-fixes in the next couple of days, get some QA coverage and > > then get it merged to master so that we can get some community testing > > early in the 3.3 cycle. > > A few quick comments: > - I think we need to amend the commit msg of the voodoo patch with the > piece of doc I've discovered. If you want I can send out a v3 with that. > - I think the HWSTAM revert is material for -next > - Can you post your 3 patches on intel-gfx, I think I can shoot at them a > bit ;-) > > acc101d drm/i915: Hold gt_lock across forcewake register reads > > Imo this is a simple cleanup (reading forcewake-protected registers isn't > really a fast-path for us), so material for -next. > > 0f0e134 drm/i915: Hold gt_lock during reset > > I still don't see what race you're trying to protect here, after all the > gpu just died, things are confusing anyway (and anyone accessing the gpu > in such a state should take that into account). Currently that's no one > afaics. So imo at most -next material. > > 176b987 drm/i915: Move reset forcewake processing to gen6_do_reset > > Again this is imo just a cleanup. Furthermore the commit msg is lying a > bit because it fails to mention the fix to use the forcewake function > pointer. So the cleanup is imo for -next and the bugfix is really old, > see: Meh, mutt mail fail, I've hit the wrong key when I've tried to look up the reference for that patch mail. Here we go: http://lists.freedesktop.org/archives/intel-gfx/2011-November/013668.html And the resend: http://www.mail-archive.com/intel-gfx@lists.freedesktop.org/msg07229.html Yours, Daniel -- Daniel Vetter Mail: daniel@ffwll.ch Mobile: +41 (0)79 365 57 48