[Intel-gfx] [PATCH 1/5] drm/i915: Try to avoid pps_{lock, unlock}() on DP ports

[Jani Nikula]

On Mon, 24 Nov 2014, Egbert Eich <eich at suse.de> wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
>
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_dp.c | 48 ++++++++++++++++++++++++-----------------
>  1 file changed, 28 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index 81f959d..a24c8cc7 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -807,17 +807,19 @@ intel_dp_aux_ch(struct intel_dp *intel_dp,
>  	uint32_t status;
>  	int try, clock = 0;
>  	bool has_aux_irq = HAS_AUX_IRQ(dev);
> -	bool vdd;
> +	bool vdd = false;
>  
> -	pps_lock(intel_dp);
> +	if (is_edp(intel_dp)) {
> +		pps_lock(intel_dp);

Why not add is_edp() into pps_lock()? The lockdep stuff in
edp_panel_vdd_on() could be moved after the is_edp() check.

BR,
Jani.

>  
> -	/*
> -	 * We will be called with VDD already enabled for dpcd/edid/oui reads.
> -	 * In such cases we want to leave VDD enabled and it's up to upper layers
> -	 * to turn it off. But for eg. i2c-dev access we need to turn it on/off
> -	 * ourselves.
> -	 */
> -	vdd = edp_panel_vdd_on(intel_dp);
> +		/*
> +		 * We will be called with VDD already enabled for dpcd/edid/oui reads.
> +		 * In such cases we want to leave VDD enabled and it's up to upper layers
> +		 * to turn it off. But for eg. i2c-dev access we need to turn it on/off
> +		 * ourselves.
> +		 */
> +		vdd = edp_panel_vdd_on(intel_dp);
> +	}
>  
>  	/* dp aux is extremely sensitive to irq latency, hence request the
>  	 * lowest possible wakeup latency and so prevent the cpu from going into
> @@ -924,10 +926,12 @@ out:
>  	pm_qos_update_request(&dev_priv->pm_qos, PM_QOS_DEFAULT_VALUE);
>  	intel_aux_display_runtime_put(dev_priv);
>  
> -	if (vdd)
> -		edp_panel_vdd_off(intel_dp, false);
> +	if (is_edp(intel_dp)) {
> +		if (vdd)
> +			edp_panel_vdd_off(intel_dp, false);
>  
> -	pps_unlock(intel_dp);
> +		pps_unlock(intel_dp);
> +	}
>  
>  	return ret;
>  }
> @@ -2291,18 +2295,22 @@ static void intel_enable_dp(struct intel_encoder *encoder)
>  	if (WARN_ON(dp_reg & DP_PORT_EN))
>  		return;
>  
> -	pps_lock(intel_dp);
> +	if (is_edp(intel_dp)) {
> +		pps_lock(intel_dp);
>  
> -	if (IS_VALLEYVIEW(dev))
> -		vlv_init_panel_power_sequencer(intel_dp);
> +		if (IS_VALLEYVIEW(dev))
> +			vlv_init_panel_power_sequencer(intel_dp);
>  
> -	intel_dp_enable_port(intel_dp);
> +		intel_dp_enable_port(intel_dp);
>  
> -	edp_panel_vdd_on(intel_dp);
> -	edp_panel_on(intel_dp);
> -	edp_panel_vdd_off(intel_dp, true);
> +		edp_panel_vdd_on(intel_dp);
> +		edp_panel_on(intel_dp);
> +		edp_panel_vdd_off(intel_dp, true);
>  
> -	pps_unlock(intel_dp);
> +		pps_unlock(intel_dp);
> +	} else {
> +		intel_dp_enable_port(intel_dp);
> +	}
>  
>  	if (IS_VALLEYVIEW(dev))
>  		vlv_wait_port_ready(dev_priv, dp_to_dig_port(intel_dp));
> -- 
> 1.8.4.5
>
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-- 
Jani Nikula, Intel Open Source Technology Center