[Intel-gfx] [PATCH 33/35] hack: Don't disable underrun reporting on the first error on ILK/SNB/IVB

[Ville Syrjälä]

On Fri, Jul 05, 2013 at 02:19:22PM -0300, Paulo Zanoni wrote:
> 2013/7/5  <ville.syrjala at linux.intel.com>:
> > From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> >
> > Don't want to lose them in the noise. Just let them happen.
> 
> When I was experimenting with this, I noticed that when we get
> underruns, we get thousands of underruns per second, until we fix the
> condition that is causing the underruns. With this we'll get tons and
> tons and tons of interrupts and really flood dmesg.

Yeah. It was just a hack to see if the code managed to apply the
watermarks in time before the pipe really starts to demand pixels. If
you actually configure the system so that it constantly underruns
(something we shouldn't allow, but currently we do) your dmesg will be
full of this stuff.

Clearly we can't even being to consider merging a patch like this
before we have much stricter checks to prevent such mode/plane
configurations. I guess even then some ratelimiting might be a
good idea, just in case.

-- 
Ville Syrjälä
Intel OTC