[Intel-gfx] [PATCH] drm/i915/vlv: drop punit freq staus read after setting idle

Ville Syrjälä ville.syrjala at linux.intel.com
Thu Jun 12 20:40:32 CEST 2014


On Thu, Jun 12, 2014 at 11:45:03PM +0530, S, Deepak wrote:
>  >> I was polling VLV_GTLC_SURVIVABILITY_REG and VLV_GTLC_PW_STATUS to make
>  >> sure both render and media wells and the gfx clock remain off, and I
>  >> was also monitoring vnn via svid. While that was going on I just rewrote
>  >> PUNIT_REG_GPU_FREQ_REQ to make Punit change the frequency, and sure
>  >> enough it did, and svid showed me that vnn had also changed. So it
>  >> appears there's no need to have the gfx clock on to change its frequency
>  >> on this BYT.
>  >>
>  >> I wonder if this part of the workaround was only needed on older parts.
>  >> Deepak, any ideas?
>  >
>  > Yes ville, this was added initial for older parts and force gfx clock
>  > was part of the workaround.
>  > We have not verified this on newer parts. Let me check with hw guys to
>  > see if workaround still exits and when this was fixed.
> 
> Hi Ville, Got the confirmation from HW team, this WA as been fixed in 
> latest stepping,

What's latest here? Did we ever ship any of the steppings that still
need the gfx clock force?

> we can remove the force gfx clock, mask and request 
> only the min freq when we are idle.
> 
> You will submit patch will fix or you want me to do it?

Go ahead if you have time. I'm already juggling too many things :)

-- 
Ville Syrjälä
Intel OTC



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