[Intel-gfx] [PATCH 3/3] drm/i915: Don't wait interruptible for possible plane buffer flush

[Eric Anholt]

On Wed, 25 Nov 2009 13:09:39 +0800, Zhenyu Wang <zhenyuw at linux.intel.com> wrote:
> When we setup buffer for display plane, we'll check any pending
> required GPU flush and possible make interruptible wait for flush
> complete. But that wait would be most possibly to fail in case of
> signals received for X process, which will then fail modeset process
> and put display engine in unconsistent state. The result could be
> blank screen or CPU hang, and DDX driver would always turn on outputs
> DPMS after whatever modeset fails or not.
> 
> So this one creates new helper for setup display plane buffer, and
> when needing flush using uninterruptible wait for that.

Can you explain why the modeset process is special and shouldn't be
interruptible?  It certainly seems to me like it should be interruptible
like other driver commands are.