[Intel-gfx] [PATCH v2] Partially revert "drm/i915: unconditionally use mt forcewake on hsw/ivb"

[Daniel Vetter]

On Tue, Jul 09, 2013 at 04:00:31PM -0700, Guenter Roeck wrote:
> This patch partially reverts commit 36ec8f877481449bdfa072e6adf2060869e2b970 for
> IvyBridge CPUs.
> 
> The original commit results in repeated 'Timed out waiting for forcewake old
> ack to clear' messages on a Supermicro C7H61 board (BIOS version 2.00 and 2.00b)
> with i7-3770K CPU. It ultimately results in a hangup if the system is highly
> loaded. Reverting the commit for IvyBridge CPUs fixes the issue.
> 
> Issue a warning if the CPU is IvyBridge and mt forcewake is disabled, since
> this condition can result in secondary issues.
> 
> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=60541
> Cc: Jesse Barnes <jbarnes at virtuousgeek.org>
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Cc: Mika Kuoppala <mika.kuoppala at intel.com>
> Signed-off-by: Guenter Roeck <linux at roeck-us.net>
Picked up for -fixes, thanks for the patch.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch