[Intel-gfx] [PATCH] drm/i915: Check for driver readyness before handling an underrun interrupt

[Chris Wilson]

On Fri, Feb 27, 2015 at 10:20:05AM +0200, Jani Nikula wrote:
> On Fri, 27 Feb 2015, Jani Nikula <jani.nikula at linux.intel.com> wrote:
> > On Thu, 26 Feb 2015, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> >> When we takeover from the BIOS and install our interrupt handler, the
> >> BIOS may have left us a few surprises in the form of spontaneous
> >> interrupts. (This is especially likely on hardware like 965gm where
> >> display fifo underruns are continuous and the GMCH cannot filter that
> >> interrupt souce.) As we enable our IRQ early so that we can use it
> >> during hardware probing, our interrupt handler must be prepared to
> >> handle a few sources prior to being fully configured. As such, we need
> >> to add a simple is-ready check prior to dereferencing our KMS state for
> >> reporting underruns.
> >>
> >> Reported-by: Rob Clark <rclark at redhat.com>
> >> Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1193972
> >
> > "You are not authorized to access bug #1193972. To see this bug, you
> > must first log in to an account with the appropriate permissions."
> >
> > Meh.
> 
> Pushed to drm-intel-fixes, thanks for the patch and review. If someone
> both cares and has access to the bugzilla, please update it.

Jani, I goofed...

> >>  	/* GMCH can't disable fifo underruns, filter them. */
> >>  	if (HAS_GMCH_DISPLAY(dev_priv->dev) &&
> >> -	    !__cpu_fifo_underrun_reporting_enabled(dev_priv, pipe))
> >> +	    !to_intel_crtc(crtc)->cpu_fifo_underrun_disabled)

Should be without the '!':
if (HAS_GMCH_DISPLAY(dev_priv->dev) &&
    to_intel_crtc(crtc)->cpu_fifo_underrun_disabled)
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre