Re: [PATCH] drm/i915: Split alloc from init for lrc

Chris Wilson
2015-08-18T15:06:23Z

On Tue, Aug 18, 2015 at 03:55:07PM +0100, Nick Hoath wrote:
> >This is the wrong location. Just kill set_seqno, the experiment has run
> >its course and we now have a n igt to exercise seqno wraparound.
> It has to be here as the seqno has to be initialised before it is
> used to create requests for the initialisation.

It is the wrong location as init_hw() is called as part of resume and
reset, both times where we don't want to actually touch seqno.

> According to the commit history, the seqno has to be initialised to
> non-zero for proper functioning. Is this no longer true?
> Maybe it should just be set to 1 instead of ~0-0x1000

Nope. It was set to non-zero purely to test wraparound, or rather the
call to set_seqno was added purely to test wraparound. Nowadays, we can
just set it to 1 and use explicit testing to catch bugs.
-Chris

--
Chris Wilson, Intel Open Source Technology Centre