[Intel-gfx] [PATCH v3 1/2] drm/i915: add render state initialization

[Mateo Lozano, Oscar]

Hi Mika,

> -----Original Message-----
> From: Intel-gfx [mailto:intel-gfx-bounces at lists.freedesktop.org] On Behalf Of
> Mika Kuoppala
> Sent: Tuesday, May 06, 2014 3:30 PM
> To: intel-gfx at lists.freedesktop.org
> Cc: ben at bwidawsk.net; miku at iki.fi; kristen at linux.intel.com
> Subject: [Intel-gfx] [PATCH v3 1/2] drm/i915: add render state initialization
> 
> HW guys say that it is not a cool idea to let device go into rc6 without proper 3d
> pipeline state.
> 
> For each new uninitialized context, generate a valid null render state to be run
> on context creation.

In Android, we have been seeing a problem in BDW D0 stepping (C0 is fine), in which actual rendering does not happen, even though everything seems to be healthy. The only "tell" seems to be that the pixel shader invocation count does not go up.
I wouldn´t dare say I understand why this fixes our problem, but it clearly does, so feel free to add:

Tested-by: Oscar Mateo <oscar.mateo at intel.com>

to both patches...