Re: [Intel-gfx] [PATCH 07/13] drm/i915/tc: Add a mode for the TypeC PHY's disconnected state

["Souza, Jose" <jose.souza@intel.com>]

On Tue, 2021-09-21 at 03:23 +0300, Imre Deak wrote:
> A follow-up change will start to disconnect/re-connect PHYs around AUX
> transfers and modeset enable/disables. To prepare for that add a new
> TypeC PHY disconnected mode, to help tracking the TC-cold blocking power
> domain status (no power domain in disconnected state, mode dependent
> power domain in connected state).
> 
> Cc: José Roberto de Souza <jose.souza@intel.com>
> Signed-off-by: Imre Deak <imre.deak@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display.h |  1 +
>  drivers/gpu/drm/i915/display/intel_tc.c      | 26 ++++++++++++++------
>  2 files changed, 19 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display.h b/drivers/gpu/drm/i915/display/intel_display.h
> index d425ee77aad71..87b96fed5e0ba 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.h
> +++ b/drivers/gpu/drm/i915/display/intel_display.h
> @@ -270,6 +270,7 @@ enum tc_port {
>  };
>  
>  enum tc_port_mode {
> +	TC_PORT_DISCONNECTED,
>  	TC_PORT_TBT_ALT,
>  	TC_PORT_DP_ALT,
>  	TC_PORT_LEGACY,
> diff --git a/drivers/gpu/drm/i915/display/intel_tc.c b/drivers/gpu/drm/i915/display/intel_tc.c
> index aa4c1e5e0c002..77b16a7c43466 100644
> --- a/drivers/gpu/drm/i915/display/intel_tc.c
> +++ b/drivers/gpu/drm/i915/display/intel_tc.c
> @@ -12,13 +12,14 @@
>  static const char *tc_port_mode_name(enum tc_port_mode mode)
>  {
>  	static const char * const names[] = {
> +		[TC_PORT_DISCONNECTED] = "disconnected",
>  		[TC_PORT_TBT_ALT] = "tbt-alt",
>  		[TC_PORT_DP_ALT] = "dp-alt",
>  		[TC_PORT_LEGACY] = "legacy",
>  	};
>  
>  	if (WARN_ON(mode >= ARRAY_SIZE(names)))
> -		mode = TC_PORT_TBT_ALT;
> +		mode = TC_PORT_DISCONNECTED;
>  
>  	return names[mode];
>  }
> @@ -513,10 +514,11 @@ static void icl_tc_phy_disconnect(struct intel_digital_port *dig_port)
>  	case TC_PORT_LEGACY:
>  	case TC_PORT_DP_ALT:
>  		tc_phy_take_ownership(dig_port, false);
> -		dig_port->tc_mode = TC_PORT_TBT_ALT;
> -		break;
> +		fallthrough;
>  	case TC_PORT_TBT_ALT:
> -		/* Nothing to do, we stay in TBT-alt mode */
> +		dig_port->tc_mode = TC_PORT_DISCONNECTED;
> +		fallthrough;
> +	case TC_PORT_DISCONNECTED:
>  		break;
>  	default:
>  		MISSING_CASE(dig_port->tc_mode);
> @@ -621,31 +623,34 @@ void intel_tc_port_sanitize(struct intel_digital_port *dig_port)
>  {
>  	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
>  	struct intel_encoder *encoder = &dig_port->base;
> -	intel_wakeref_t tc_cold_wref;
>  	int active_links = 0;
>  
>  	mutex_lock(&dig_port->tc_lock);
> -	tc_cold_wref = tc_cold_block(dig_port);
>  
> -	dig_port->tc_mode = intel_tc_port_get_current_mode(dig_port);
>  	if (dig_port->dp.is_mst)
>  		active_links = intel_dp_mst_encoder_active_links(dig_port);
>  	else if (encoder->base.crtc)
>  		active_links = to_intel_crtc(encoder->base.crtc)->active;
>  
> +	drm_WARN_ON(&i915->drm, dig_port->tc_mode != TC_PORT_DISCONNECTED);
>  	if (active_links) {
> +		intel_wakeref_t tc_cold_wref = tc_cold_block(dig_port);
> +
> +		dig_port->tc_mode = intel_tc_port_get_current_mode(dig_port);
> +
>  		if (!icl_tc_phy_is_connected(dig_port))
>  			drm_dbg_kms(&i915->drm,
>  				    "Port %s: PHY disconnected with %d active link(s)\n",
>  				    dig_port->tc_port_name, active_links);
>  		intel_tc_port_link_init_refcount(dig_port, active_links);
> +
> +		tc_cold_unblock(dig_port, tc_cold_wref);
>  	}
>  
>  	drm_dbg_kms(&i915->drm, "Port %s: sanitize mode (%s)\n",
>  		    dig_port->tc_port_name,
>  		    tc_port_mode_name(dig_port->tc_mode));
>  
> -	tc_cold_unblock(dig_port, tc_cold_wref);
>  	mutex_unlock(&dig_port->tc_lock);
>  }
>  
> @@ -704,6 +709,10 @@ static void __intel_tc_port_lock(struct intel_digital_port *dig_port,
>  		tc_cold_unblock(dig_port, tc_cold_wref);
>  	}
>  
> +	drm_WARN_ON(&i915->drm, dig_port->tc_mode == TC_PORT_DISCONNECTED);

This warning will be printed everytime it goes to suspend, other than that lgtm.

> +	drm_WARN_ON(&i915->drm, dig_port->tc_mode != TC_PORT_TBT_ALT &&
> +				!tc_phy_is_owned(dig_port));
> +
>  	drm_WARN_ON(&i915->drm, dig_port->tc_lock_wakeref);
>  	dig_port->tc_lock_wakeref = wakeref;
>  }
> @@ -816,6 +825,7 @@ void intel_tc_port_init(struct intel_digital_port *dig_port, bool is_legacy)
>  
>  	mutex_init(&dig_port->tc_lock);
>  	dig_port->tc_legacy_port = is_legacy;
> +	dig_port->tc_mode = TC_PORT_DISCONNECTED;
>  	dig_port->tc_link_refcount = 0;
>  	tc_port_load_fia_params(i915, dig_port);
>  }