[Intel-gfx] [PATCH v2 12/17] drm/i915: Store the watermark latency values in dev_priv

[Chris Wilson]

On Mon, Aug 05, 2013 at 06:25:54PM +0200, Daniel Vetter wrote:
> On Thu, Aug 01, 2013 at 03:23:56PM +0100, Chris Wilson wrote:
> > On Thu, Aug 01, 2013 at 04:18:50PM +0300, ville.syrjala at linux.intel.com wrote:
> > > From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > > 
> > > Rather than having to read the latency values out every time, just
> > > store them in dev_priv.
> > > 
> > > On ILK and IVB there is a difference between some of the latency
> > > values for different planes, so store the latency values for each
> > > plane type separately, and apply the necesary fixups during init.
> > > 
> > > v2: Fix some checkpatch complaints
> > 
> > As you are now storing these, it would also be useful to add a debugfs
> > file to dump them out for sanity checking. I leave the request to adjust
> > them via debugfs to somebody else ;-)
> 
> I guess since this is ramping up to be the furture plane_config we might
> just need a bit of plane config dump support. Of course we need to be
> careful to not redump on every nuclear pageflip, but only if something
> interesting changes ...
> 
> Or did you just think of the underlying latency values that steer the wm
> comuptation?

Here I was just thinking of the latency values. We should be able to
eyeball them for consistency, and, if need be, use pen and paper to sanity
check our calculations. That's made a whole lot more convenient if the
kernel tells us exactly what it is using, perhaps with the raw register
values thrown in as well for the next level in paranoia.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre