[Intel-gfx] [PATCH] drm/i915: tune down the fast link training vs boot fail

[Daniel Vetter]

On Tue, Dec 13, 2016 at 10:23:05PM +0200, Ville Syrjälä wrote:
> On Tue, Dec 13, 2016 at 08:54:14PM +0100, Daniel Vetter wrote:
> > It's been unfixed since a while and no one is immediately working on
> > this. And we have the FIXME already. And now also a task in the DP
> > team's backlog.
> > 
> > Cc: Linus Torvalds <torvalds at linux-foundation.org>
> > Cc: stable at vger.kernel.org
> > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > References: https://lists.freedesktop.org/archives/intel-gfx/2016-July/101951.html
> > Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
> > ---
> > Hi Linus,
> > 
> > Feel free to apply directly in case it annoys too much and you don't
> > want to wait for your presents ;-)
> > 
> > Cheers, Daniel
> > ---
> >  drivers/gpu/drm/i915/intel_dp.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> > index db75bb924e48..6e875d42642a 100644
> > --- a/drivers/gpu/drm/i915/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/intel_dp.c
> > @@ -4014,8 +4014,8 @@ intel_dp_check_link_status(struct intel_dp *intel_dp)
> >  		return;
> >  
> >  	/* FIXME: we need to synchronize this sort of stuff with hardware
> > -	 * readout */
> > -	if (WARN_ON_ONCE(!intel_dp->lane_count))
> > +	 * readout. Currently fast link training doesn't work on boot-up. */
> 
> s/fast link training/link retraining/ is what I'd put there.

Adjusted ...
> 
> I'm a bit sad to hide it but doesn't look like the proper solution is
> going to happen any time soon.
> 
> Acked-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

... and merged since CI seems to approve too ;-)
-Daniel

> 

> > +	if (!intel_dp->lane_count)
> >  		return;
> >  
> >  	/* if link training is requested we should perform it always */
> > -- 
> > 2.11.0
> 
> -- 
> Ville Syrjälä
> Intel OTC

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch