[Intel-gfx] [PATCH 11/12 v2] drm/i915: wait render timeout ioctl

[Chris Wilson]

On Sat, 28 Apr 2012 19:11:34 -0700, Ben Widawsky <ben at bwidawsk.net> wrote:
> On Fri, 27 Apr 2012 16:24:24 +0100
> Chris Wilson <chris at chris-wilson.co.uk> wrote:
> 
> > On Thu, 26 Apr 2012 16:03:08 -0700, Ben Widawsky <ben at bwidawsk.net>
> > wrote:
> > > This helps implement glClientWaitSync.
> > > 
> > > Finally we can use the new timed seqno waiting function to allow
> > > userspace to wait on a request with a timeout. This implements that
> > > interface.
> > > 
> > > The new ioctl is very straight forward, there is a flags field
> > > which I envision may be useful for various flush permutations of
> > > the command.
> > 
> > What are the semantics of the ioctl? A simple use case would help
> > specify the interface here.
> 
> The first time I sent out the series, I included the libdrm and igt
> test. Is this what you're looking for, or something in the commit
> message?

Whilst we will be bound by the API as used forever and a day, I found I
could not review the code against the interface for any aberrant
behaviour...

I'd at least like to some justification for the form of the interface in
the changelog and some indication of expected behaviour. That block
should be good enough also to include next to the ioctl so that we have
some ideas of what userspace is expecting when reviewing the code later.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre