[Intel-gfx] [PATCH] drm/i915: don't call swsci_setup on resume

[Daniel Vetter]

On Thu, Feb 6, 2014 at 4:32 PM, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> On Thu, Feb 06, 2014 at 01:19:48PM -0200, Paulo Zanoni wrote:
>> From: Paulo Zanoni <paulo.r.zanoni at intel.com>
>>
>> This function is used to discover which swsci callbacks the machine
>> supports. It calls swsci() 3 times, and usually takes a considerable
>> number of milliseconds to finish.
>>
>> I don't see a reason for a change on the supported callbacks between
>> boot and resume, so use the values retrieved at boot time forever,
>> making resume a little bit faster.
>
> This looks unsafe following a hibernate resume where the system could
> change around us. Across a suspend resume, you can argue that we do not
> need to shootdown OpRegion (and not just swsci) at all.

See my other mail, but I think _init/_fini take care of all this. The
only exception would be if the bios moves the opregion around, but
that's only really possible if you update it or change your machine
otherwise. Then you get both pieces anyway.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch