[Intel-gfx] enabling forcewake from userspace

[Ben Widawsky]

On Fri, Mar 25, 2011 at 07:07:48PM -0700, Ben Widawsky wrote:
> 
> Chris, do you already have something like this queued up?
> 
> I don't have a SNB with which to test this patch right now. I'd like to
> know if anyone has any major issues with this, because I intend to use
> this to enable userspace to properly read and write registers on SNB.

So right after hitting 'y' I realized how much I detest this. It leaves
buggy usespace the opportunity to allow the GPU to never sleep. However,
I'd really like to find a solution to allow intel_reg_read and
intel_reg_write to work properly on GEN6.

Chris' idea from IRC of using LOAD/STORE_REGISTER will not work unless
we use a secure batch buffer.

The only other option floating around is IOCTLs to read/write the
registers, which previously seemed like a bad idea, but is now looking
like the only option.

Ben