[Intel-gfx] [PATCH] drm/i915/dp: Reset the link params on HPD/connected boot/resume

[Manasi Navare]

On Tue, Feb 14, 2017 at 09:08:25PM +0200, Ville Syrjälä wrote:
> On Tue, Feb 07, 2017 at 04:54:11PM -0800, Manasi Navare wrote:
> > The max link parameters should be set/reset only on HPD or
> > connected boot case or on system resume.
> > 
> > Add a flag reset_link_params to intel_dp to decide when
> > to reset the max link parameters. This prevents the parameters
> > from getting reset/overwritten through all other
> > connector->funcs->detect() calls. This is important when link
> > training fails and the max link params are modified to the
> > lower fallback values.
> > 
> > Cc: Ville Syrjala <ville.syrjala at linux.intel.com>
> > Signed-off-by: Manasi Navare <manasi.d.navare at intel.com>
> 
> Looks all right to me. Though I suppose this conflicts with Jani's
> changes?
> 
> Anyways
> Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
>

Thanks for the review.
With Jani's changes only the name changes to max_link_rate and max_link_lane_count.
But the logic remains the same.
I have tested this on top of Jani's patches and it works great.
If this gets merged, Jani's  patch will have to be rebased on top of this else
vice versa if Jani's patches get merged first.

Regards
Manasi 
> > ---
> >  drivers/gpu/drm/i915/intel_dp.c  | 16 ++++++++++++----
> >  drivers/gpu/drm/i915/intel_drv.h |  1 +
> >  2 files changed, 13 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> > index 21924cf..ed28788b 100644
> > --- a/drivers/gpu/drm/i915/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/intel_dp.c
> > @@ -4624,11 +4624,15 @@ intel_dp_long_pulse(struct intel_connector *intel_connector)
> >  		      yesno(intel_dp_source_supports_hbr2(intel_dp)),
> >  		      yesno(drm_dp_tps3_supported(intel_dp->dpcd)));
> >  
> > -	/* Set the max lane count for sink */
> > -	intel_dp->max_sink_lane_count = drm_dp_max_lane_count(intel_dp->dpcd);
> > +	if (intel_dp->reset_link_params) {
> > +		/* Set the max lane count for sink */
> > +		intel_dp->max_sink_lane_count = drm_dp_max_lane_count(intel_dp->dpcd);
> >  
> > -	/* Set the max link BW for sink */
> > -	intel_dp->max_sink_link_bw = intel_dp_max_link_bw(intel_dp);
> > +		/* Set the max link BW for sink */
> > +		intel_dp->max_sink_link_bw = intel_dp_max_link_bw(intel_dp);
> > +
> > +		intel_dp->reset_link_params = false;
> > +	}
> >  
> >  	intel_dp_print_rates(intel_dp);
> >  
> > @@ -5010,6 +5014,8 @@ void intel_dp_encoder_reset(struct drm_encoder *encoder)
> >  	if (lspcon->active)
> >  		lspcon_resume(lspcon);
> >  
> > +	intel_dp->reset_link_params = true;
> > +
> >  	pps_lock(intel_dp);
> >  
> >  	if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
> > @@ -5079,6 +5085,7 @@ intel_dp_hpd_pulse(struct intel_digital_port *intel_dig_port, bool long_hpd)
> >  		      long_hpd ? "long" : "short");
> >  
> >  	if (long_hpd) {
> > +		intel_dp->reset_link_params = true;
> >  		intel_dp->detect_done = false;
> >  		return IRQ_NONE;
> >  	}
> > @@ -5920,6 +5927,7 @@ intel_dp_init_connector(struct intel_digital_port *intel_dig_port,
> >  		 intel_dig_port->max_lanes, port_name(port)))
> >  		return false;
> >  
> > +	intel_dp->reset_link_params = true;
> >  	intel_dp->pps_pipe = INVALID_PIPE;
> >  	intel_dp->active_pipe = INVALID_PIPE;
> >  
> > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> > index fbe5c72..f579776 100644
> > --- a/drivers/gpu/drm/i915/intel_drv.h
> > +++ b/drivers/gpu/drm/i915/intel_drv.h
> > @@ -923,6 +923,7 @@ struct intel_dp {
> >  	bool has_audio;
> >  	bool detect_done;
> >  	bool channel_eq_status;
> > +	bool reset_link_params;
> >  	enum hdmi_force_audio force_audio;
> >  	bool limited_color_range;
> >  	bool color_range_auto;
> > -- 
> > 2.1.4
> 
> -- 
> Ville Syrjälä
> Intel OTC