[Intel-gfx] [PATCH 0/5] drm/i915: Optimize plane updates a bit

[Maarten Lankhorst]

Hey,

Op 09-03-17 om 16:44 schreef ville.syrjala at linux.intel.com:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
>
> Now that commit e1edbd44e23b ("drm/i915: Complain if we take too
> long under vblank evasion.") has expose just how badly we suck,
> it seems like a good time to optimize things a little bit.
>
> Prior to this one of my VLV machines exceed the 100 usec vblank
> evade deadline pretty regularly, and at ever boot I was hitting
> numbers as high as 500 usec. Granted that was with lockdep and
> all kinds of other debug things enabled. After these changes
> things seem stay below the 33 usec mark, and with all that debug
> junk enabled we seem to staying below 22 usec.
>
> Note that I was testing single plane updates mostly, so I'm
> not 100% sure multi plane updates couldn't still exceed the
> deadline. That will need to be checked.
I've considered doing the same before, but thanks to the commit it's clear that it seems to worth the effort to do so.
Maybe a bit more radical, but could we grab the uncore lock for the entire update perhaps if it's still an issue?

Patch series looks sane, might be worth fixing all chips at some point. :)

Assuming testbot is happy..

Reviewed-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>

~Maarten