[Intel-gfx] [PATCH v2 2/6] drm/i915/dp: Restrict link retrain workaround to external monitors

[Dhinakaran Pandiyan]

On Mon, 2018-10-01 at 12:49 -0700, Rodrigo Vivi wrote:
> On Mon, Sep 24, 2018 at 03:45:24PM -0700, Dhinakaran Pandiyan wrote:
> > Commit '3cf71bc9904d ("drm/i915: Re-apply "Perform link quality
> > check,
> > unconditionally during long pulse"")' applies a work around for
> > sinks
> 
> Fixes: ?

I had second thoughts about Fixes: when I wrote the patch, but now I
think it does make sense to cherry-pick to v4.19. 

> 
> Should this patch be on drm-intel-fixes for 4.19?
> 
> If so, the cherry-pick failed anyway and a backported version is
> needed.

I'll send a backported a version.

Thanks
DK
> 
> Please let me know how to proceed here.
> 
> Thanks in advance,
> Rodrigo.
> 
> > that don't signal link loss. The work around does not need to have
> > to be
> > that broad as the issue was seen with only one particular monitor;
> > limit
> > this only for external displays as eDP features like PSR turn off
> > the link
> > and the driver ends up retraining the link seeeing that link is not
> > synchronized.
> > 
> > Cc: Lyude Paul <lyude at redhat.com>
> > Cc: Jan-Marek Glogowski <glogow at fbihome.de>
> > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> > References: 3cf71bc9904d ("drm/i915: Re-apply "Perform link quality
> > check, unconditionally during long pulse"")
> > Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_dp.c | 13 +++++++------
> >  1 file changed, 7 insertions(+), 6 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_dp.c
> > b/drivers/gpu/drm/i915/intel_dp.c
> > index 34c561011e7a..6130d05d8b88 100644
> > --- a/drivers/gpu/drm/i915/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/intel_dp.c
> > @@ -5072,12 +5072,13 @@ intel_dp_long_pulse(struct intel_connector
> > *connector,
> >  		 */
> >  		status = connector_status_disconnected;
> >  		goto out;
> > -	} else {
> > -		/*
> > -		 * Some external monitors do not signal loss of link
> > -		 * synchronization with an IRQ_HPD, so force a link
> > status
> > -		 * check.
> > -		 */
> > +	}
> > +
> > +	/*
> > +	 * Some external monitors do not signal loss of link
> > synchronization
> > +	 * with an IRQ_HPD, so force a link status check.
> > +	 */
> > +	if (!intel_dp_is_edp(intel_dp)) {
> >  		struct intel_encoder *encoder =
> > &dp_to_dig_port(intel_dp)->base;
> >  
> >  		intel_dp_retrain_link(encoder, ctx);
> > -- 
> > 2.17.1
> > 
> > _______________________________________________
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> > Intel-gfx at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx