Date: Sat, 22 Jun 2013 12:16:46 -0700
From: Jesse Barnes <jbarnes@virtuousgeek.org>
To: Guenter Roeck <linux@roeck-us.net>
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: <20130622121646.0afcc207@jbarnes-desktop>
In-Reply-To: <20130622065808.GA20980@roeck-us.net>
References: <20130622065808.GA20980@roeck-us.net>
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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...

-- 
Jesse Barnes, Intel Open Source Technology Center
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