[Intel-gfx] [PATCH 2/2] drm/i915/psr: Add debugfs support to force a downgrade to PSR1 mode.

[Dhinakaran Pandiyan]

On Wed, 2018-08-08 at 16:19 +0200, Maarten Lankhorst wrote:
> This will make it easier to test PSR1 on PSR2 capable eDP machines.
> 
> Changes since v1:
> - Remove I915_PSR_DEBUG_FORCE_PSR2, it did nothing, not sure forcing
>   PSR2 would even work.
> - Handle NULL crtc in intel_psr_set_debugfs_mode. (dhnkrn)
> 
Reviewed-by: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>


> Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/i915_drv.h  |  1 +
>  drivers/gpu/drm/i915/intel_psr.c | 44 ++++++++++++++++++++++++++++
> ----
>  2 files changed, 40 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.h
> b/drivers/gpu/drm/i915/i915_drv.h
> index a3ea48ce1811..14883614d9e6 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -616,6 +616,7 @@ struct i915_psr {
>  #define I915_PSR_DEBUG_DEFAULT		0x00
>  #define I915_PSR_DEBUG_DISABLE		0x01
>  #define I915_PSR_DEBUG_ENABLE		0x02
> +#define I915_PSR_DEBUG_FORCE_PSR1	0x03
>  #define I915_PSR_DEBUG_IRQ		0x10
>  
>  	u32 debug;
> diff --git a/drivers/gpu/drm/i915/intel_psr.c
> b/drivers/gpu/drm/i915/intel_psr.c
> index 12fbc59af5a4..a408faa16f90 100644
> --- a/drivers/gpu/drm/i915/intel_psr.c
> +++ b/drivers/gpu/drm/i915/intel_psr.c
> @@ -68,6 +68,17 @@ static bool psr_global_enabled(u32 debug)
>  	}
>  }
>  
> +static bool intel_psr2_enabled(struct drm_i915_private *dev_priv,
> +			       const struct intel_crtc_state
> *crtc_state)
> +{
> +	switch (dev_priv->psr.debug & I915_PSR_DEBUG_MODE_MASK) {
> +	case I915_PSR_DEBUG_FORCE_PSR1:
> +		return false;
> +	default:
> +		return crtc_state->has_psr2;
> +	}
> +}
> +
>  void intel_psr_irq_control(struct drm_i915_private *dev_priv, bool
> debug)
>  {
>  	u32 debug_mask, mask;
> @@ -646,7 +657,7 @@ void intel_psr_enable(struct intel_dp *intel_dp,
>  		goto unlock;
>  	}
>  
> -	dev_priv->psr.psr2_enabled = crtc_state->has_psr2;
> +	dev_priv->psr.psr2_enabled = intel_psr2_enabled(dev_priv,
> crtc_state);
>  	dev_priv->psr.busy_frontbuffer_bits = 0;
>  	dev_priv->psr.prepared = true;
>  
> @@ -820,19 +831,38 @@ static bool __psr_wait_for_idle_locked(struct
> drm_i915_private *dev_priv)
>  	return err == 0 && dev_priv->psr.enabled;
>  }
>  
> +static bool switching_psr(struct drm_i915_private *dev_priv,
> +			  struct intel_crtc_state *crtc_state,
> +			  u32 mode)
> +{
> +	/* Can't switch psr state anyway if PSR2 is not supported.
> */
> +	if (!crtc_state || !crtc_state->has_psr2)
> +		return false;
> +
> +	if (dev_priv->psr.psr2_enabled && mode ==
> I915_PSR_DEBUG_FORCE_PSR1)
> +		return true;
> +
> +	if (!dev_priv->psr.psr2_enabled && mode !=
> I915_PSR_DEBUG_FORCE_PSR1)
> +		return true;
> +
> +	return false;
> +}
> +
>  int intel_psr_set_debugfs_mode(struct drm_i915_private *dev_priv,
>  			       struct drm_modeset_acquire_ctx *ctx,
>  			       u64 val)
>  {
>  	struct drm_device *dev = &dev_priv->drm;
>  	struct drm_connector_state *conn_state;
> +	struct intel_crtc_state *crtc_state = NULL;
>  	struct drm_crtc *crtc;
>  	struct intel_dp *dp;
>  	int ret;
>  	bool enable;
> +	u32 mode = val & I915_PSR_DEBUG_MODE_MASK;
>  
>  	if (val & ~(I915_PSR_DEBUG_IRQ | I915_PSR_DEBUG_MODE_MASK)
> ||
> -	    (val & I915_PSR_DEBUG_MODE_MASK) >
> I915_PSR_DEBUG_ENABLE) {
> +	    mode > I915_PSR_DEBUG_FORCE_PSR1) {
>  		DRM_DEBUG_KMS("Invalid debug mask %llx\n", val);
>  		return -EINVAL;
>  	}
> @@ -850,7 +880,8 @@ int intel_psr_set_debugfs_mode(struct
> drm_i915_private *dev_priv,
>  		if (ret)
>  			return ret;
>  
> -		ret = wait_for_completion_interruptible(&crtc-
> >state->commit->hw_done);
> +		crtc_state = to_intel_crtc_state(crtc->state);
> +		ret = wait_for_completion_interruptible(&crtc_state-
> >base.commit->hw_done);
>  	} else
>  		ret = wait_for_completion_interruptible(&conn_state-
> >commit->hw_done);
>  
> @@ -863,14 +894,17 @@ int intel_psr_set_debugfs_mode(struct
> drm_i915_private *dev_priv,
>  
>  	enable = psr_global_enabled(val);
>  
> -	if (!enable)
> +	if (!enable || switching_psr(dev_priv, crtc_state, mode))
>  		intel_psr_disable_locked(dev_priv->psr.dp);
>  
>  	dev_priv->psr.debug = val;
> +	if (crtc)
> +		dev_priv->psr.psr2_enabled =
> intel_psr2_enabled(dev_priv, crtc_state);
> +
>  	intel_psr_irq_control(dev_priv, dev_priv->psr.debug &
> I915_PSR_DEBUG_IRQ);
>  
>  	if (dev_priv->psr.prepared && enable)
> -		intel_psr_enable_locked(dev_priv,
> to_intel_crtc_state(crtc->state));
> +		intel_psr_enable_locked(dev_priv, crtc_state);
>  
>  	mutex_unlock(&dev_priv->psr.lock);
>  	return ret;