[Intel-gfx] [PATCH 07/23] drm/i915: add forcewake functions that don't touch runtime PM

[Daniel Vetter]

On Thu, Feb 27, 2014 at 07:26:34PM -0300, Paulo Zanoni wrote:
> From: Paulo Zanoni <paulo.r.zanoni at intel.com>
> 
> To solve a chicken-and-egg problem. Currently when we get/put
> forcewake we also get/put runtime PM and this works fine because the
> runtime PM code doesn't need forcewake. But we're going to merge PC8
> and runtime PM into a single feature, and the PC8 code (the LCPLL
> code) does need the forcewake, so that specific piece of code needs to
> call the _no_rpm version so it doesn't try to get runtime PM in the
> code that gets runtime PM.
> 
> For now the new functions are unused, we'll use them on the patch that
> merges PC8 with runtime PM.
> 
> Also notice that, so simplify things, the put() function doesn't use
> the workqueue, since the workqueue also puts runtime PM.
> 
> Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>

See my previous mail, but I'm still freaked out about this. Doing runtime
pm hidden deep down in our register I/O functions is imo rather deeply
troubling ... I'll punt for now on this.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch