[Intel-gfx] [PATCH 3/6] drm/i915/dp_mst: Move clearing the ACT sent flag closer to its polling

[Ville Syrjälä]

On Tue, Jun 16, 2020 at 05:18:52PM +0300, Imre Deak wrote:
> During transcoder enabling we'll configure the transcoder in MST mode
> and enable the VC payload allocation, which will start the ACT sequence.
> Before waiting for the ACT sequence completion, we need to clear the ACT
> sent flag, but based on the above we can do this right before enabling
> the transcoder.
> 
> For clarity, move the flag clearing closer to where we wait for it.
> 
> While at it also factor out some common code.
> 
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Signed-off-by: Imre Deak <imre.deak at intel.com>

Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

> ---
>  drivers/gpu/drm/i915/display/intel_dp_mst.c | 36 +++++++++++++--------
>  1 file changed, 23 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> index 2e6c6375a23b..3977ee4f7176 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> @@ -317,6 +317,25 @@ intel_dp_mst_atomic_check(struct drm_connector *connector,
>  	return ret;
>  }
>  
> +static void clear_act_sent(struct intel_dp *intel_dp)
> +{
> +	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
> +
> +	intel_de_write(i915, intel_dp->regs.dp_tp_status,
> +		       intel_de_read(i915, intel_dp->regs.dp_tp_status));
> +}
> +
> +static void wait_for_act_sent(struct intel_dp *intel_dp)
> +{
> +	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
> +
> +	if (intel_de_wait_for_set(i915, intel_dp->regs.dp_tp_status,
> +				  DP_TP_STATUS_ACT_SENT, 1))
> +		drm_err(&i915->drm, "Timed out waiting for ACT sent\n");
> +
> +	drm_dp_check_act_status(&intel_dp->mst_mgr);
> +}
> +
>  static void intel_mst_disable_dp(struct intel_atomic_state *state,
>  				 struct intel_encoder *encoder,
>  				 const struct intel_crtc_state *old_crtc_state,
> @@ -377,11 +396,7 @@ static void intel_mst_post_disable_dp(struct intel_atomic_state *state,
>  		       TRANS_DDI_FUNC_CTL(old_crtc_state->cpu_transcoder),
>  		       val);
>  
> -	if (intel_de_wait_for_set(dev_priv, intel_dp->regs.dp_tp_status,
> -				  DP_TP_STATUS_ACT_SENT, 1))
> -		drm_err(&dev_priv->drm,
> -			"Timed out waiting for ACT sent when disabling\n");
> -	drm_dp_check_act_status(&intel_dp->mst_mgr);
> +	wait_for_act_sent(intel_dp);
>  
>  	drm_dp_mst_deallocate_vcpi(&intel_dp->mst_mgr, connector->port);
>  
> @@ -452,7 +467,6 @@ static void intel_mst_pre_enable_dp(struct intel_atomic_state *state,
>  	struct intel_connector *connector =
>  		to_intel_connector(conn_state->connector);
>  	int ret;
> -	u32 temp;
>  	bool first_mst_stream;
>  
>  	/* MST encoders are bound to a crtc, not to a connector,
> @@ -485,8 +499,6 @@ static void intel_mst_pre_enable_dp(struct intel_atomic_state *state,
>  		drm_err(&dev_priv->drm, "failed to allocate vcpi\n");
>  
>  	intel_dp->active_mst_links++;
> -	temp = intel_de_read(dev_priv, intel_dp->regs.dp_tp_status);
> -	intel_de_write(dev_priv, intel_dp->regs.dp_tp_status, temp);
>  
>  	ret = drm_dp_update_payload_part1(&intel_dp->mst_mgr);
>  
> @@ -517,16 +529,14 @@ static void intel_mst_enable_dp(struct intel_atomic_state *state,
>  
>  	drm_WARN_ON(&dev_priv->drm, pipe_config->has_pch_encoder);
>  
> +	clear_act_sent(intel_dp);
> +
>  	intel_ddi_enable_transcoder_func(encoder, pipe_config);
>  
>  	drm_dbg_kms(&dev_priv->drm, "active links %d\n",
>  		    intel_dp->active_mst_links);
>  
> -	if (intel_de_wait_for_set(dev_priv, intel_dp->regs.dp_tp_status,
> -				  DP_TP_STATUS_ACT_SENT, 1))
> -		drm_err(&dev_priv->drm, "Timed out waiting for ACT sent\n");
> -
> -	drm_dp_check_act_status(&intel_dp->mst_mgr);
> +	wait_for_act_sent(intel_dp);
>  
>  	drm_dp_update_payload_part2(&intel_dp->mst_mgr);
>  
> -- 
> 2.23.1

-- 
Ville Syrjälä
Intel