[Intel-gfx] [PATCH] drm/i915: restore the early forcewake cleanup

[Daniel Vetter]

On Sun, Nov 17, 2013 at 11:53 AM, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> On Sat, Nov 16, 2013 at 04:00:09PM +0100, Daniel Vetter wrote:
>> Some BIOS just leak the forcewak bits, which we clean up.
>> Unfortunately this has been broken in
>>
>> commit 521198a2e7095c8c7daa8d7d3a76a110c346be6f
>> Author: Mika Kuoppala <mika.kuoppala at linux.intel.com>
>> Date:   Fri Aug 23 16:52:30 2013 +0300
>>
>>     drm/i915: sanitize forcewake registers on reset
>>
>> To make this work both for resets and for BIOS takeover just add the
>> forcewake clearing call back to intel_uncore_early_sanitize.
>
> The call to intel_uncore_forcewake_reset() is in
> intel_uncore_sanitize(). Do you mind explaining the dependence that
> causes us to require an ealry_sanitize?  There's no issue in doing so,
> just the change log feels inaccurate.

Yeah I've forgotten to write down my analysis:

"We need to clear the forcewake in early sanitize so that the forcewak
dance in intel_uncore_init (to figure out whether we have mt or legacy
forcewake on ivb) works. That cleanup fits in nicely with the general
topic of early_sanitize to prepare for the very first mmio ops."

I'll add this to the commit message.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch