[Intel-gfx] [PATCH] drm/i915: Scale ring, rather than ia, frequency on Haswell

[Daniel Vetter]

On Wed, Apr 10, 2013 at 08:45:11PM +0100, Chris Wilson wrote:
> Haswell introduces a separate frequency domain for the ring (uncore). So
> where we used to increase the CPU (IA) clock with GPU busyness, we now
> need to scale the ring frequency directly instead. As the ring limits
> our memory bandwidth, it is vital for performance that when the GPU is
> busy, we increase the frequency of the ring to increase the available
> memory bandwidth.
> 
> v2: Fix the algorithm to actually use the scaled gpu frequency for the ring.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Jesse Barnes <jbarnes at virtuousgeek.org>

I think this is another reason to split hsw rps code from snb/ivb. I think
I'll wait until Rodrigo's patch is in, and then apply this.

Call me a scared chicken, but I kinda am wrt rps stuff ;-)
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch