Re: [PATCH 1/5] drm/i915: don't write powered down IRQ registers on Gen 8

Daniel Vetter
2014-07-08T14:57:53Z

On Tue, Jul 08, 2014 at 11:15:03AM -0300, Paulo Zanoni wrote:
> 2014-07-07 18:23 GMT-03:00 Daniel Vetter <daniel@ffwll.ch>:
> > On Fri, Jul 04, 2014 at 11:50:29AM -0300, Paulo Zanoni wrote:
> >> From: Paulo Zanoni <paulo.r.zanoni@intel.com>
> >>
> >> If we enable unclaimed register reporting on Gen 8, we will discover
> >> that the IRQ registers for pipes B and C are also on the power well,
> >> so writes to them when the power well is disabled result in unclaimed
> >> register errors.
> >>
> >> Also, hsw_power_well_post_enable() already takes care of re-enabling
> >> them once the power well is enabled.
> >>
> >> Testcase: igt/pm_rpm/rte
> >> Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
> >
> > Hm, shouldn't we split this into only setting up pipe A here and the pipe
> > B stuff once we fire up the power well?
> >
>
> No because these functions might be called when the power wells are
> already enabled.

Hm, where does this still happen? bdw has power well support and chv has a
different display block ...

This code changed too often and I have no idea any more what's up and
what's down here ;-)
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch