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

[Ville Syrjälä]

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>

> ---
>  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