[Intel-gfx] [PATCH 2/2] drm/i915: Defer late hardware initialisation until first open

[Chris Wilson]

On Tue, Jun 30, 2015 at 04:01:11PM +0100, Dave Gordon wrote:
> We can do less work during driver load by deferring some of it until
> the first time the device is opened; in particular, the function
> i915_gem_init_hw_late() introduced by the previous patch. This should
> allow the system to get out of the early single-threaded phase of
> system initialisation and into full multi-user mode somewhat quicker.
> 
> In addition, we expect that by the time of the first open, not only
> the driver's software structures but also system-specific items such
> as filesystem mounting have been fully initialised, meaning that the
> late initialisation code can run in a much more complete environment
> than the driver_load stage presents. This can be important for
> embedded programmable devices that need firmware loaded from a file
> before they can be used.

No. It delays establising the power contexts. Something that in the past
we have been told must be done asap. You can move it to an async worker,
that would be achieve the goals stated here, and not be dependent on a
cooperating userspace.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre