[Intel-gfx] [PATCH 3/3] drm/i915/psr: Avoid initializing PSR if there is no sink support.

[Rodrigo Vivi]

On Wed, Jan 03, 2018 at 09:38:24PM +0000, Dhinakaran Pandiyan wrote:
> DPCD read for the eDP is complete by the time intel_psr_init() is
> called, which means we can avoid initializing PSR structures and state
> if there is no sink support.
> 
> Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>

sorry for the delay on this. you had responded to my questions on previous
thread and after reading your response again and applying the code it made sense
why to use sink_support instead of CAN_PSR on init.

Reviewed-by: Rodrigo Vivi <rodrigo.vivi at intel.com>

> ---
>  drivers/gpu/drm/i915/i915_debugfs.c | 7 ++++++-
>  drivers/gpu/drm/i915/intel_psr.c    | 9 +++++++++
>  2 files changed, 15 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index 6890340387b7..cc659b4b2a45 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -2521,14 +2521,19 @@ static int i915_edp_psr_status(struct seq_file *m, void *data)
>  	u32 stat[3];
>  	enum pipe pipe;
>  	bool enabled = false;
> +	bool sink_support;
>  
>  	if (!HAS_PSR(dev_priv))
>  		return -ENODEV;
>  
> +	sink_support = dev_priv->psr.sink_support;
> +	seq_printf(m, "Sink_Support: %s\n", yesno(sink_support));
> +	if (!sink_support)
> +		return 0;
> +
>  	intel_runtime_pm_get(dev_priv);
>  
>  	mutex_lock(&dev_priv->psr.lock);
> -	seq_printf(m, "Sink_Support: %s\n", yesno(dev_priv->psr.sink_support));
>  	seq_printf(m, "Enabled: %s\n", yesno((bool)dev_priv->psr.enabled));
>  	seq_printf(m, "Active: %s\n", yesno(dev_priv->psr.active));
>  	seq_printf(m, "Busy frontbuffer bits: 0x%03x\n",
> diff --git a/drivers/gpu/drm/i915/intel_psr.c b/drivers/gpu/drm/i915/intel_psr.c
> index df9b1d7baefb..863650366425 100644
> --- a/drivers/gpu/drm/i915/intel_psr.c
> +++ b/drivers/gpu/drm/i915/intel_psr.c
> @@ -503,6 +503,9 @@ void intel_psr_enable(struct intel_dp *intel_dp,
>  	if (!crtc_state->has_psr)
>  		return;
>  
> +	if (WARN_ON(!CAN_PSR(dev_priv)))
> +		return;
> +
>  	WARN_ON(dev_priv->drrs.dp);
>  	mutex_lock(&dev_priv->psr.lock);
>  	if (dev_priv->psr.enabled) {
> @@ -633,6 +636,9 @@ void intel_psr_disable(struct intel_dp *intel_dp,
>  	if (!old_crtc_state->has_psr)
>  		return;
>  
> +	if (WARN_ON(!CAN_PSR(dev_priv)))
> +		return;
> +
>  	mutex_lock(&dev_priv->psr.lock);
>  	if (!dev_priv->psr.enabled) {
>  		mutex_unlock(&dev_priv->psr.lock);
> @@ -913,6 +919,9 @@ void intel_psr_init(struct drm_i915_private *dev_priv)
>  	dev_priv->psr_mmio_base = IS_HASWELL(dev_priv) ?
>  		HSW_EDP_PSR_BASE : BDW_EDP_PSR_BASE;
>  
> +	if (!dev_priv->psr.sink_support)
> +		return;
> +
>  	/* Per platform default: all disabled. */
>  	if (i915_modparams.enable_psr == -1)
>  		i915_modparams.enable_psr = 0;
> -- 
> 2.11.0
>