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

[Jani Nikula]

On Fri, 27 Feb 2015, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> 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)

It never happened.

BR,
Jani.


> -Chris
>
> -- 
> Chris Wilson, Intel Open Source Technology Centre

-- 
Jani Nikula, Intel Open Source Technology Center