[Intel-gfx] [PATCH v2 4/6] drm/i915/psr: Do not print last attempted entry or exit in PSR debugfs while in PSR2

[Dhinakaran Pandiyan]

On Thu, 2019-01-03 at 06:21 -0800, José Roberto de Souza wrote:
> PSR2 only trigger interruptions for AUX error, so let's not print
> useless information in debugfs.
> Also adding a comment to intel_psr_irq_handler() about that.
> 
Is it worth keeping this stuff for PSR1 if PSR2 is not supported, did
not work well enough for PSR1 IGTs either. In any case, are these
interrupts present on ICL?


> v2: Warning and not letting user set PSR_DEBUG_IRQ when PSR2 is
> enabled(Dhinakaran)
> 
> Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
> Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_debugfs.c | 6 +++++-
>  drivers/gpu/drm/i915/intel_psr.c    | 1 +
>  2 files changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c
> b/drivers/gpu/drm/i915/i915_debugfs.c
> index 77b097b50fd5..5ebf0e647ac7 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -2621,7 +2621,7 @@ static int i915_edp_psr_status(struct seq_file
> *m, void *data)
>  		seq_printf(m, "Performance counter: %u\n", val);
>  	}
>  
> -	if (psr->debug & I915_PSR_DEBUG_IRQ) {
> +	if ((psr->debug & I915_PSR_DEBUG_IRQ) && !psr->psr2_enabled) {
Is there a case where PSR2 and IRQ debug are enabled now that you
disallow setting of this value?


>  		seq_printf(m, "Last attempted entry at: %lld\n",
>  			   psr->last_entry_attempt);
>  		seq_printf(m, "Last exit at: %lld\n", psr->last_exit);
> @@ -2676,6 +2676,10 @@ i915_edp_psr_debug_set(void *data, u64 val)
>  skip_mode:
>  	if (!ret) {
>  		mutex_lock(&dev_priv->psr.lock);
> +		if (dev_priv->psr.psr2_enabled && (val &
> I915_PSR_DEBUG_IRQ)) {
> +			val &= ~I915_PSR_DEBUG_IRQ;
> +			DRM_WARN("PSR debug IRQ cannot be enabled with
> PSR2");

WARN is inconsistent with DEBUG level logging that this function
already uses.

> +		}
>  		dev_priv->psr.debug = val;
>  		intel_psr_irq_control(dev_priv, dev_priv->psr.debug);
We are accessing hardware outside of rpm_get()/rpm_put() here.


>  		mutex_unlock(&dev_priv->psr.lock);
> diff --git a/drivers/gpu/drm/i915/intel_psr.c
> b/drivers/gpu/drm/i915/intel_psr.c
> index bba4f7da68b3..a875546880fa 100644
> --- a/drivers/gpu/drm/i915/intel_psr.c
> +++ b/drivers/gpu/drm/i915/intel_psr.c
> @@ -201,6 +201,7 @@ void intel_psr_irq_handler(struct
> drm_i915_private *dev_priv, u32 psr_iir)
>  			mask |= EDP_PSR_ERROR(shift);
>  		}
>  
> +		/* PSR2 don't trigger PRE_ENTRY and POST_EXIT
> interruptions */
>  		if (psr_iir & EDP_PSR_PRE_ENTRY(shift)) {
>  			dev_priv->psr.last_entry_attempt = time_ns;
>  			DRM_DEBUG_KMS("[transcoder %s] PSR entry
> attempt in 2 vblanks\n",