[Intel-gfx] [PATCH] drm/i915: Fix irq enable tracking in driver load

[Jani Nikula]

On Thu, 04 Sep 2014, Daniel Vetter <daniel at ffwll.ch> wrote:
> On Thu, Sep 04, 2014 at 02:12:10PM +0300, Jani Nikula wrote:
>> On Wed, 27 Aug 2014, Daniel Vetter <daniel.vetter at ffwll.ch> wrote:
>> > A bunch of warnings fire on some ->irq_postinstall hooks since those
>> > can enable interrupts (e.g. rps interrupts). And then our ordering
>> > self-checks fire and complain.
>> >
>> > To fix that set the tracking boolen before enabling the irqs witho
>> > drm_irq_install. Quoting the discussion with Jesse why that's safe:
>> 
>> Yi Sun's testing result needs to be addressed one way or another before
>> merging this:
>> 
>> http://mid.gmane.org/D9F66AA509623343B6A9A3D4502D5A52112B0676@SHSMSX101.ccr.corp.intel.com
>
> Shrug it off as an unstable test result. Both mine and Jesse's patch
> really only change the logic we use to WARN about interrupt state. We
> don't use pm._irqs_disabled for anything else at all.

Okay, so this is a PITA to review, but at least
ironlake_enable_display_irq will behave differently during
drm_irq_install because of this patch.

Jani.

> Which means that black screen is at most a timing issue. Or the baseline
> kernels don't perfectly match (the new warning in Jesse's patch is a bit
> an indicator for that).
> -Daniel
> -- 
> Daniel Vetter
> Software Engineer, Intel Corporation
> +41 (0) 79 365 57 48 - http://blog.ffwll.ch

-- 
Jani Nikula, Intel Open Source Technology Center