[Intel-gfx] [PATCH 2/7] drm/i915: Fix PSR disable sequence on core platforms.

[Zanoni, Paulo R]

Em Qui, 2015-08-20 às 17:55 -0700, Rodrigo Vivi escreveu:
> According to spec the disable sequence is:
> Driver will do the following on PSR Disable.
> 1. Disable PSR in PSR control register, SRD_CTL[bit 31].
> 2. Poll on PSR idle
> 3. Wait for VBlank
> 4. Disable VSC DIP.

Shouldn't this be done at intel_psr_exit() instead  of
intel_psr_disable()?

In case it's yes (which is my guess), then the wait_for_vblank() is
probably going to slow down everything, so we may need to use some sort
of delayed work.

In case it's no, then I don't think we need the wait_for_vblank() since
the encoder disable only happens after the pipe disable.

> 
> Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
> ---
>  drivers/gpu/drm/i915/intel_psr.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/intel_psr.c 
> b/drivers/gpu/drm/i915/intel_psr.c
> index 51f0514..92e2b467 100644
> --- a/drivers/gpu/drm/i915/intel_psr.c
> +++ b/drivers/gpu/drm/i915/intel_psr.c
> @@ -459,6 +459,10 @@ static void hsw_psr_disable(struct intel_dp 
> *intel_dp)
>  	struct intel_digital_port *intel_dig_port = 
> dp_to_dig_port(intel_dp);
>  	struct drm_device *dev = intel_dig_port->base.base.dev;
>  	struct drm_i915_private *dev_priv = dev->dev_private;
> +	struct drm_crtc *crtc = intel_dig_port->base.base.crtc;
> +	enum pipe pipe = to_intel_crtc(crtc)->pipe;
> +	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
> +	u32 ctl_reg = HSW_TVIDEO_DIP_CTL(intel_crtc->config
> ->cpu_transcoder);
>  
>  	if (dev_priv->psr.active) {
>  		I915_WRITE(EDP_PSR_CTL(dev),
> @@ -469,6 +473,12 @@ static void hsw_psr_disable(struct intel_dp 
> *intel_dp)
>  			       EDP_PSR_STATUS_STATE_MASK) == 0, 
> 2000, 10))
>  			DRM_ERROR("Timed out waiting for PSR Idle 
> State\n");
>  
> +		intel_wait_for_vblank(dev, pipe);
> +
> +		I915_WRITE(ctl_reg, I915_READ(ctl_reg)
> +			   & ~VIDEO_DIP_ENABLE_VSC_HSW);
> +		POSTING_READ(ctl_reg);
> +
>  		dev_priv->psr.active = false;
>  	} else {
>  		WARN_ON(I915_READ(EDP_PSR_CTL(dev)) & 
> EDP_PSR_ENABLE);