[Intel-gfx] [PATCH v3] drm/i915: resize the GuC WOPCM for rc6

[Nick Hoath]

On 05/05/2016 16:04, Dave Gordon wrote:
> On 05/05/2016 15:02, Antoine, Peter wrote:
>> The attached version still does not explain that the WOPCM_TOP is to tell the GuC not to use that space.
>
> That's NOT what WOPCM_TOP means. The GuC is allowed to use the space up
> to the value stored in the GUC_WOPCM_SIZE register (as the comment above
> the #define says). Architecturally, this is allowed to be any value
> greater than (16K+sizeof internal SRAM (64, 128, or 256K)) and less than
> or equal to GUC_WOPCM_TOP (which is a platform-independent constant), so
> we normally choose the maximm allowed. Howver on BXT, we need to leave
> some space at the top for the RC6 image, hence the logic (and comments!)
> in guc_wopcm_size().
>
>> The extra information does not aid anybody as the information is used internally within the GuC.
> It may help the next person who has to figure out what's gone wrong on
> some future chip that needs more than 64K for RC6!
>
> .Dave.
>>
>> But, I have not actual objection to the patch.
>>
>> Peter.
>>
>
Unfortunately Dave's patch locked my test system on bootup, so I've t-b 
& r-b'd Peter's.