[PATCH 05/10] drm/i915/psr: enable ALPM for psr2

[Jim Bride]

On Mon, Jan 02, 2017 at 05:00:58PM +0530, vathsala nagaraju wrote:
> As per edp1.4 spec , alpm is required for psr2 operation as it's
> used for all psr2  main link power down management and alpm enable
> bit must be set for psr2 operation.
> 
> Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> Cc: Jim Bride <jim.bride at linux.intel.com>
> Signed-off-by: vathsala nagaraju <vathsala.nagaraju at intel.com>
> Signed-off-by: Patil Deepti <deepti.patil at intel.com>

Reviewed-by: Jim Bride <jim.bride at linux.intel.com>

> ---
>  drivers/gpu/drm/i915/i915_drv.h  |  1 +
>  drivers/gpu/drm/i915/intel_dp.c  | 10 ++++++++++
>  drivers/gpu/drm/i915/intel_psr.c |  6 +++++-
>  3 files changed, 16 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 36dc835..0742b81 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1166,6 +1166,7 @@ struct i915_psr {
>  	bool link_standby;
>  	bool y_cord_support;
>  	bool colorimetry_support;
> +	bool alpm;
>  };
>  
>  enum intel_pch {
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index da577c9..9b313a3 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -3060,6 +3060,14 @@ static bool intel_dp_get_colorimetry_status(struct intel_dp *intel_dp)
>  	return dprx & DP_VSC_SDP_EXT_FOR_COLORIMETRY_SUPPORTED;
>  }
>  
> +bool intel_dp_get_alpm_status(struct intel_dp *intel_dp)
> +{
> +	uint8_t alpm_caps = 0;
> +
> +	drm_dp_dpcd_readb(&intel_dp->aux, DP_RECEIVER_ALPM_CAP, &alpm_caps);
> +	return alpm_caps & DP_ALPM_CAP;
> +}
> +
>  /* These are source-specific values. */
>  uint8_t
>  intel_dp_voltage_max(struct intel_dp *intel_dp)
> @@ -3644,6 +3652,8 @@ void intel_dp_set_idle_link_train(struct intel_dp *intel_dp)
>  				intel_dp_get_y_cord_status(intel_dp);
>  			dev_priv->psr.colorimetry_support =
>  				intel_dp_get_colorimetry_status(intel_dp);
> +			dev_priv->psr.alpm =
> +				intel_dp_get_alpm_status(intel_dp);
>  		}
>  
>  	}
> diff --git a/drivers/gpu/drm/i915/intel_psr.c b/drivers/gpu/drm/i915/intel_psr.c
> index 93eb0f0..494e4b2 100644
> --- a/drivers/gpu/drm/i915/intel_psr.c
> +++ b/drivers/gpu/drm/i915/intel_psr.c
> @@ -209,7 +209,11 @@ static void hsw_psr_enable_sink(struct intel_dp *intel_dp)
>  		drm_dp_dpcd_writeb(&intel_dp->aux,
>  				DP_SINK_DEVICE_AUX_FRAME_SYNC_CONF,
>  				DP_AUX_FRAME_SYNC_ENABLE);
> -
> +	/* Enable ALPM at sink for psr2 */
> +	if (dev_priv->psr.psr2_support && dev_priv->psr.alpm)
> +		drm_dp_dpcd_writeb(&intel_dp->aux,
> +				DP_RECEIVER_ALPM_CONFIG,
> +				DP_ALPM_ENABLE);
>  	if (dev_priv->psr.link_standby)
>  		drm_dp_dpcd_writeb(&intel_dp->aux, DP_PSR_EN_CFG,
>  				   DP_PSR_ENABLE | DP_PSR_MAIN_LINK_ACTIVE);
> -- 
> 1.9.1