From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jesse Barnes <jbarnes@virtuousgeek.org>
Subject: Re: [PATCH] drm: Aggressively disable vblanks
Date: Mon, 20 Dec 2010 20:03:53 -0800
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To: Andrew Lutomirski <luto@mit.edu>
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On Mon, 20 Dec 2010 22:55:46 -0500
Andrew Lutomirski <luto@mit.edu> wrote:

> On Mon, Dec 20, 2010 at 10:47 PM, Keith Packard <keithp@keithp.com> wrote:
> > On Mon, 20 Dec 2010 22:34:12 -0500, Andrew Lutomirski <luto@mit.edu> wrote:
> >
> >> But five seconds is a *long* time, and anything short enough that the
> >> interrupt actually gets turned off in normal use risks the same race.
> >
> > Right, so eliminating any race seems like the basic requirement. Can
> > that be done?
> 
> I'll give it a shot.
> 
> Do you know if there's an existing tool to call drm_wait_vblank from
> userspace for testing?  I know approximately nothing about libdrm or
> any userspace graphics stuff whatsoever.

Yeah, libdrm has a test program called vbltest; it should do what you
need.

-- 
Jesse Barnes, Intel Open Source Technology Center