[Intel-gfx] [PATCH 00/19] drm/i915: More HSW watermark prep work

[ville.syrjala at linux.intel.com]

Another big set of prep work to get the watermarks ready for the atomic
age.

The main themes here are some new structures to allow us to eventually
pre-compute the watermarks and trying to reduce the overhead of the
watermark update itself.

My plan has been to attempt to update the watermarks from the vblank irq
handler, but I'm not 100% sure that I can do that. I have a big patch set
at [1] that does it (and more), and for the most part it is working. But
I am seeing an occasional underrun (very rarely though). I'm not sure
that's caused by missing the dealine in the vblank handler or something
else.

In my big patch set, the next step is adding the vblank update mechanism,
and after that convert ILK/SNB/IVB over to the HSW watermark code. As I'm
not yet 100% convinced that the vblank thing will work out, I think I will
reverse those steps, so that we can get the ILK+ stuff in while I keep
looking into the underrun issue a bit more.

The big patchset also has some other random bits and pieces (mainly
sprite related), and I'll probably be sending some of that out as well.

[1] git://gitorious.org/vsyrjala/linux.git watermarks_full