[Intel-gfx] [PATCH 2/2] drm/i915: Document the multi-threaded FORCEWAKE bits

[Jesse Barnes]

On Wed, 17 Oct 2012 12:09:55 +0100
Chris Wilson <chris at chris-wilson.co.uk> wrote:

> No functional change, but reserves 0x2 for use by userspace.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>  drivers/gpu/drm/i915/i915_reg.h |    2 ++
>  drivers/gpu/drm/i915/intel_pm.c |   10 +++++-----
>  2 files changed, 7 insertions(+), 5 deletions(-)

Each of the bits in this reg correspond to a specific agent that may
need to wake the GT.  Unfortunately I don't have docs about which bits
are used by which agents.  IIRC the BIOS uses one as does the AMT
engine if present.

I'll try to find out who owns each and maybe we can reserve our own for
userspace.

Thanks,
-- 
Jesse Barnes, Intel Open Source Technology Center