[Intel-gfx] [PATCH] drm/i915: Force PSR exit when IRQ_HPD is detected on eDP.

[Rodrigo Vivi]

Hi Ville,

Is it better now?
Could you please review this patch?

Thanks,
Rodrigo.

On Wed, Nov 18, 2015 at 11:19 AM, Rodrigo Vivi <rodrigo.vivi at intel.com> wrote:
> According to VESA spec: "If a Source device receives and IRQ_HPD
> while in a PSR active state, and cannot identify what caused the
> IRQ_HPD to be generated, based on Sink device status registers,
> the Source device can take implementation-specific action.
> One such action can be to exit and then re-enter a PSR active
> state."
>
> Since we aren't checking for any sink status registers and we
>  aren't looking for any other implementation-specific action,
> in case we receive any IRQ_HPD and psr is active let's force
> the exit and reschedule it back.
>
> v2: IRQ_HPD means short HPD so handle it correctly
>     as Ville pointed out.
>
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
> ---
>  drivers/gpu/drm/i915/intel_dp.c  |  3 +++
>  drivers/gpu/drm/i915/intel_drv.h |  1 +
>  drivers/gpu/drm/i915/intel_psr.c | 33 +++++++++++++++++++++++++++++++++
>  3 files changed, 37 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index bec443a..ca7a798 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -5004,6 +5004,9 @@ intel_dp_hpd_pulse(struct intel_digital_port *intel_dig_port, bool long_hpd)
>                         goto mst_fail;
>                 }
>         } else {
> +               if (intel_dig_port->base.type == INTEL_OUTPUT_EDP)
> +                       intel_psr_irq_hpd(dev);
> +
>                 if (intel_dp->is_mst) {
>                         if (intel_dp_check_mst_status(intel_dp) == -EINVAL)
>                                 goto mst_fail;
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index ab5c147..1d61551 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -1401,6 +1401,7 @@ void intel_psr_flush(struct drm_device *dev,
>  void intel_psr_init(struct drm_device *dev);
>  void intel_psr_single_frame_update(struct drm_device *dev,
>                                    unsigned frontbuffer_bits);
> +void intel_psr_irq_hpd(struct drm_device *dev);
>
>  /* intel_runtime_pm.c */
>  int intel_power_domains_init(struct drm_i915_private *);
> diff --git a/drivers/gpu/drm/i915/intel_psr.c b/drivers/gpu/drm/i915/intel_psr.c
> index bc5ea2a..465d36b 100644
> --- a/drivers/gpu/drm/i915/intel_psr.c
> +++ b/drivers/gpu/drm/i915/intel_psr.c
> @@ -765,6 +765,39 @@ void intel_psr_flush(struct drm_device *dev,
>  }
>
>  /**
> + * intel_psr_irq_hpd - Let PSR aware of IRQ_HPD
> + * @dev: DRM device
> + *
> + * This function is called when IRQ_HPD is received on eDP.
> + */
> +void intel_psr_irq_hpd(struct drm_device *dev)
> +{
> +       struct drm_i915_private *dev_priv = dev->dev_private;
> +       int delay_ms = HAS_DDI(dev) ? 100 : 500;
> +
> +       mutex_lock(&dev_priv->psr.lock);
> +
> +       /*
> +        * According to VESA spec "If a Source device receives and IRQ_HPD
> +        * while in a PSR active state, and cannot identify what caused the
> +        * IRQ_HPD to be generated, based on Sink device status registers,
> +        * the Source device can take implementation-specific action.
> +        * One such action can be to exit and then re-enter a PSR active
> +        * state." Since we aren't checking for any sink status registers
> +        * and we aren't looking for any other implementation-specific
> +        * action, in case we receive any IRQ_HPD and psr is active let's
> +        * force the exit and reschedule it back.
> +        */
> +       if (dev_priv->psr.active) {
> +               intel_psr_exit(dev);
> +               schedule_delayed_work(&dev_priv->psr.work,
> +                                     msecs_to_jiffies(delay_ms));
> +       }
> +
> +       mutex_unlock(&dev_priv->psr.lock);
> +}
> +
> +/**
>   * intel_psr_init - Init basic PSR work and mutex.
>   * @dev: DRM device
>   *
> --
> 2.4.3
>
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-- 
Rodrigo Vivi
Blog: http://blog.vivi.eng.br