[Intel-gfx] [PATCH] drm/i915: Fix error handling during DPRX link training

[Imre Deak]

On Tue, Oct 27, 2020 at 10:02:45AM -0400, Jason Andryuk wrote:
> On Tue, Oct 27, 2020 at 9:36 AM Imre Deak <imre.deak at intel.com> wrote:
> >
> > Make sure to propagate the error result from the DPRX link training
> > phase. The lack of this broke the link training fall-back logic if the
> > link training failed during the DPRX phase.
> >
> > Fixes: b30edfd8d0b4 ("drm/i915: Switch to LTTPR non-transparent mode link training")
> > References: https://gitlab.freedesktop.org/drm/intel/-/issues/1378
> > Reported-by: Jason Andryuk <jandryuk at gmail.com>
> > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > Signed-off-by: Imre Deak <imre.deak at intel.com>
> 
> Reviewed-by: Jason Andryuk <jandryuk at gmail.com>

Thanks.

> I haven't tested, but I assume this will cause my 7200 to fail link
> training (channel equalization) and cause the flashing display.  Any
> suggestions there?  Would a quirk like
> https://lore.kernel.org/lkml/20201023124804.11457-1-jandryuk@gmail.com/
> be acceptable?

I'd like to try finding the root cause, if you could provide some more
logs on the gitlab ticket (will follow-up there).

> 
> Regards,
> Jason