[Intel-gfx] [PATCH 06/11] drm/i915/psr: Add intel_psr_activate_block_get()/put()

[Souza, Jose]

On Mon, 2018-04-02 at 11:20 -0700, Rodrigo Vivi wrote:
> On Fri, Mar 30, 2018 at 03:23:31PM -0700, José Roberto de Souza
> wrote:
> > intel_psr_activate_block_get() should be called when by some reason
> > PSR should not be activated for some time, it will increment
> > counter
> > and it should the decremented by intel_psr_activate_block_put()
> > when PSR can be activated again.
> > intel_psr_activate_block_put() will not actually activate PSR,
> > users
> > of this function should also call intel_psr_activate().
> 
> Ohh cool! you made the counter.
> probably we will need to change things from mutex to spin locker.
> But also the blocker functions here could already introduce the
> function
> calls to really block and release psr.

Oh so drop the 'drm/i915/psr: Export intel_psr_activate/exit()' and
call PSR exit and activate from intel_psr_activate_block_get()/put()?

I dind't understand why you want to change struct mutex lock; to
spinlock_t?

> 
> > 
> > Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
> > Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
> > Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> > ---
> >  drivers/gpu/drm/i915/i915_drv.h  |  1 +
> >  drivers/gpu/drm/i915/intel_drv.h |  2 ++
> >  drivers/gpu/drm/i915/intel_psr.c | 54
> > ++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 57 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_drv.h
> > b/drivers/gpu/drm/i915/i915_drv.h
> > index 99af9169d792..41ebb144594e 100644
> > --- a/drivers/gpu/drm/i915/i915_drv.h
> > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > @@ -609,6 +609,7 @@ struct i915_psr {
> >  	bool has_hw_tracking;
> >  	bool psr2_enabled;
> >  	u8 sink_sync_latency;
> > +	unsigned int activate_block_count;
> >  
> >  	void (*enable_source)(struct intel_dp *,
> >  			      const struct intel_crtc_state *);
> > diff --git a/drivers/gpu/drm/i915/intel_drv.h
> > b/drivers/gpu/drm/i915/intel_drv.h
> > index 70026b772721..020b96324135 100644
> > --- a/drivers/gpu/drm/i915/intel_drv.h
> > +++ b/drivers/gpu/drm/i915/intel_drv.h
> > @@ -1893,6 +1893,8 @@ void intel_psr_compute_config(struct intel_dp
> > *intel_dp,
> >  			      struct intel_crtc_state
> > *crtc_state);
> >  void intel_psr_exit(struct intel_dp *intel_dp, bool wait_idle);
> >  void intel_psr_activate(struct intel_dp *intel_dp, bool schedule);
> > +void intel_psr_activate_block_get(struct intel_dp *intel_dp);
> > +void intel_psr_activate_block_put(struct intel_dp *intel_dp);
> >  
> >  /* 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 906a12ea934d..8702dbafb42d 100644
> > --- a/drivers/gpu/drm/i915/intel_psr.c
> > +++ b/drivers/gpu/drm/i915/intel_psr.c
> > @@ -558,6 +558,8 @@ static void __intel_psr_activate(struct
> > intel_dp *intel_dp)
> >  
> >  	WARN_ON(dev_priv->psr.active);
> >  	lockdep_assert_held(&dev_priv->psr.lock);
> > +	if (dev_priv->psr.activate_block_count)
> > +		return;
> >  
> >  	dev_priv->psr.activate(intel_dp);
> >  	dev_priv->psr.active = true;
> > @@ -1188,3 +1190,55 @@ void intel_psr_activate(struct intel_dp
> > *intel_dp, bool schedule)
> >  out:
> >  	mutex_unlock(&dev_priv->psr.lock);
> >  }
> > +
> > +/**
> > + * intel_psr_activate_block_get - Block further attempts to
> > activate PSR
> > + * @intel_dp: DisplayPort that have PSR enabled
> > + *
> > + * It have a internal reference count, so each
> > intel_psr_activate_block_get()
> > + * should have a intel_psr_activate_block_put() counterpart.
> > + */
> > +void intel_psr_activate_block_get(struct intel_dp *intel_dp)
> > +{
> > +	struct intel_digital_port *dig_port =
> > dp_to_dig_port(intel_dp);
> > +	struct drm_device *dev = dig_port->base.base.dev;
> > +	struct drm_i915_private *dev_priv = to_i915(dev);
> > +
> > +	if (!CAN_PSR(dev_priv))
> > +		return;
> > +
> > +	mutex_lock(&dev_priv->psr.lock);
> > +	if (dev_priv->psr.enabled != intel_dp)
> > +		goto out;
> > +
> > +	dev_priv->psr.activate_block_count++;
> > +out:
> > +	mutex_unlock(&dev_priv->psr.lock);
> > +}
> > +
> > +
> > +/**
> > + * intel_psr_activate_block_put - Unblock further attempts to
> > activate PSR
> > + * @intel_dp: DisplayPort that have PSR enabled
> > + *
> > + * Decrease the reference counter incremented by
> > intel_psr_activate_block_get()
> > + * when zero it allows PSR be activate. To actually activate PSR
> > when reference
> > + * counter is zero intel_psr_activate() should be called.
> > + */
> > +void intel_psr_activate_block_put(struct intel_dp *intel_dp)
> > +{
> > +	struct intel_digital_port *dig_port =
> > dp_to_dig_port(intel_dp);
> > +	struct drm_device *dev = dig_port->base.base.dev;
> > +	struct drm_i915_private *dev_priv = to_i915(dev);
> > +
> > +	if (!CAN_PSR(dev_priv))
> > +		return;
> > +
> > +	mutex_lock(&dev_priv->psr.lock);
> > +	if (dev_priv->psr.enabled != intel_dp)
> > +		goto out;
> > +
> > +	dev_priv->psr.activate_block_count--;
> > +out:
> > +	mutex_unlock(&dev_priv->psr.lock);
> > +}
> > -- 
> > 2.16.3
> >