Re: [Intel-gfx] [PATCH 2/2] drm/i915/display: Add warn_on in intel_psr_pause()

["Kahola, Mika" <mika.kahola@intel.com>]

> -----Original Message-----
> From: Souza, Jose <jose.souza@intel.com>
> Sent: Wednesday, October 20, 2021 3:36 AM
> To: intel-gfx@lists.freedesktop.org
> Cc: Kahola, Mika <mika.kahola@intel.com>; Hogander, Jouni
> <jouni.hogander@intel.com>; Sripada, Radhakrishna
> <radhakrishna.sripada@intel.com>; Souza, Jose <jose.souza@intel.com>
> Subject: [PATCH 2/2] drm/i915/display: Add warn_on in intel_psr_pause()
> 
> Right now the only user of psr_pause/resume is intel_cdclk but additional users
> will be added in the future and we may need do reference counting for PSR
> pause and resume, for now only adding a warn_on so this cases do not go
> unnoticed.
> 
> Cc: Mika Kahola <mika.kahola@intel.com>
> Cc: Jouni Hogander <jouni.hogander@intel.com>
> Cc: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
> Signed-off-by: José Roberto de Souza <jose.souza@intel.com>

For the time being, the warn_on seems a valid addition to remind us about these cases.

Reviewed-by: Mika Kahola <mika.kahola@intel.com>

> ---
>  drivers/gpu/drm/i915/display/intel_psr.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_psr.c
> b/drivers/gpu/drm/i915/display/intel_psr.c
> index 7a205fd5023bb..49c2dfbd40554 100644
> --- a/drivers/gpu/drm/i915/display/intel_psr.c
> +++ b/drivers/gpu/drm/i915/display/intel_psr.c
> @@ -1346,6 +1346,7 @@ void intel_psr_disable(struct intel_dp *intel_dp,
>   */
>  void intel_psr_pause(struct intel_dp *intel_dp)  {
> +	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
>  	struct intel_psr *psr = &intel_dp->psr;
> 
>  	if (!CAN_PSR(intel_dp))
> @@ -1358,6 +1359,9 @@ void intel_psr_pause(struct intel_dp *intel_dp)
>  		return;
>  	}
> 
> +	/* If we ever hit this, we will need to add refcount to pause/resume */
> +	drm_WARN_ON(&dev_priv->drm, psr->paused);
> +
>  	intel_psr_exit(intel_dp);
>  	intel_psr_wait_exit_locked(intel_dp);
>  	psr->paused = true;
> --
> 2.33.1