Date: Sat, 22 Jun 2013 13:04:09 -0700
From: Guenter Roeck <linux@roeck-us.net>
To: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
        linux-kernel@vger.kernel.org, Mika Kuoppala <mika.kuoppala@intel.com>,
        Daniel Vetter <daniel.vetter@ffwll.ch>,
        David Airlie <airlied@linux.ie>
Subject: Re: 'Timed out waiting for forcewake old ack to clear' and hangup on
 IvyBridge system
Message-ID: <20130622200409.GA24545@roeck-us.net>
References: <20130622065808.GA20980@roeck-us.net>
 <20130622121646.0afcc207@jbarnes-desktop>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20130622121646.0afcc207@jbarnes-desktop>
User-Agent: Mutt/1.5.21 (2010-09-15)
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1978
Lines: 44

On Sat, Jun 22, 2013 at 12:16:46PM -0700, Jesse Barnes wrote:
> On Fri, 21 Jun 2013 23:58:08 -0700
> Guenter Roeck <linux@roeck-us.net> wrote:
> 
> > Hi all,
> > 
> > after upgrading one of my servers to 3.8, then 3.9.7 and 3.10-rc6, I started to
> > see lots of "Timed out waiting for forcewake old ack to clear" error messages,
> > including hang-ups especially if the system was highly loaded. With 3.5.24
> > everything was fine.
> > 
> > After backing out commit 36ec8f877 (drm/i915: unconditionally use mt forcewake
> > on hsw/ivb), everything is back to normal. The log message is still there, but
> > only once during boot, and the system runs stable.
> > 
> > CPU is "Intel(R) Core(TM) i7-3770K CPU @ 3.50GHz", mainboard is Supermicro
> > C7H61, BIOS version 2.00 dated 11/02/2012. Configuration file is whatever
> > comes with Ubuntu; I'll be happy to provide a copy if anyone thinks it might
> > help.
> > 
> > Any idea what else I can do besides using a special kernel with the backed out
> > commit ? Is it possible that others have the same problem ?
> 
> Ouch, so a BIOS that uses the other forcewake mechanism seems to have
> escaped.  Is there a newer one available for your system?  I'm hoping
> it'll fix the issue, otherwise we may have to introduce both methods
> for IVB again...
> 
I installed the latest BIOS version (2.00b), but it did not fix the problem.

Is there some info (such as an Intel document describing what needs to be done)
which I could pass on to Supermicro ?

I think it would be helpful if the condition was detected and reported, if that
is possible. I spent two days so far tracking this down. It would be nice
if others would not have to go through the same experience.

Thanks,
Guenter
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/