[Intel-gfx] [PATCH 2/4] drm/i915: put ring frequency and turbo setup into a work queue v3

[Chris Wilson]

On Wed, 31 Oct 2012 15:41:03 -0700, Jesse Barnes <jbarnes at virtuousgeek.org> wrote:
> Communicating via the mailbox registers with the PCU can take quite
> awhile.  And updating the ring frequency or enabling turbo is not
> something that needs to happen synchronously, so take it out of our init
> and resume paths to speed things up (~200ms on my T420).
> 
> v2: add comment about why we use a work queue (Daniel)
>     make sure work queue is idle on suspend (Daniel)
>     use a delayed work queue since there's no hurry (Daniel)
> v3: make cleanup symmetric and just call cancel work directly (Daniel)
> 
> References: https://bugs.freedesktop.org/show_bug.cgi?id=54089

Use round_jiffies_up_relative(HZ) to compute the delay to align the
wakeup with others.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre