[Intel-gfx] [PATCH 0/3] Fixes for HPD

[Ville Syrjälä]

On Fri, Jun 17, 2016 at 06:04:11PM -0400, Lyude wrote:
> Forgot to mention, Ville: if you could get me an example of how to get
> vlv into an infinite loop with these patches I'd appreciate that. I
> haven't been able to reproduce this at all with the Valleyview machine
> I've got here.

Whether it goes totally wild or not might depend on amount of
logging/debug features/etc. But it's not terribly hard to see
that there is a problem by just reading the code.

> 
> On Fri, 2016-06-17 at 17:58 -0400, Lyude wrote:
> > These are a couple of patches intended to fix one of the big problems
> > we have
> > with a lot of chipsets on i915 right now: in the various forms of
> > suspend we
> > use in the driver, many of them break HPD while active and can lead
> > to some
> > seriously confusing situations where they can't get their monitors to
> > turn on.
> > 
> > The patches here for fixing Valleyview need to be used with Ville
> > Syrjälä's
> > patchset for (partially?) preventing valleyview from getting in an
> > infinite hpd
> > detect loop when doing polling:
> > 
> > https://patchwork.freedesktop.org/series/5884/
> > 
> > It should also be noted some of these are resends, since the original
> > patches
> > never got picked up by patchwork
> > 
> > Lyude (3):
> >   drm/i915/vlv: Make intel_crt_reset() per-encoder
> >   drm/i915/vlv: Reset the ADPA in vlv_display_power_well_init()
> >   drm/i915: Enable polling when we don't have hpd
> > 
> > Cc: stable at vger.kernel.org
> > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > Cc: Daniel Vetter <daniel.vetter at intel.com>
> > 
> >  drivers/gpu/drm/i915/i915_drv.c         |  7 +++-
> >  drivers/gpu/drm/i915/i915_drv.h         |  3 ++
> >  drivers/gpu/drm/i915/intel_crt.c        | 10 ++---
> >  drivers/gpu/drm/i915/intel_drv.h        |  4 +-
> >  drivers/gpu/drm/i915/intel_hotplug.c    | 69
> > ++++++++++++++++++++++++++++-----
> >  drivers/gpu/drm/i915/intel_runtime_pm.c | 10 +++++
> >  6 files changed, 86 insertions(+), 17 deletions(-)
> > 
> -- 
> Cheers,
> 	Lyude

-- 
Ville Syrjälä
Intel OTC