[Intel-gfx] [PATCH v2 8/9] drm/dp: Release DP MST shared link bandwidth

[Pandiyan, Dhinakaran]

On Wed, 2017-01-25 at 07:16 +0100, Daniel Vetter wrote:
> On Tue, Jan 24, 2017 at 03:49:36PM -0800, Dhinakaran Pandiyan wrote:
> > Implement the ->atomic_release() callback to release the shared link
> > bandwidth that was originally acquired during compute_config()
> > 
> > Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_dp_mst.c | 28 ++++++++++++++++++++++++++++
> >  1 file changed, 28 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c
> > index f51574f..2f57a56 100644
> > --- a/drivers/gpu/drm/i915/intel_dp_mst.c
> > +++ b/drivers/gpu/drm/i915/intel_dp_mst.c
> > @@ -78,6 +78,33 @@ static bool intel_dp_mst_compute_config(struct intel_encoder *encoder,
> >  
> >  }
> >  
> > +static void intel_dp_mst_atomic_release(struct drm_connector *connector,
> > +					struct drm_connector_state *conn_state)
> > +{
> > +	struct intel_dp_mst_encoder *intel_mst;
> > +	struct drm_dp_mst_topology_mgr *mgr;
> > +	struct drm_dp_mst_topology_state *topology_state;
> > +	struct drm_encoder *encoder;
> > +	struct intel_connector *intel_connector = to_intel_connector(connector);
> > +
> > +	encoder = connector->state->best_encoder;
> > +	if (!encoder || to_intel_encoder(encoder)->type != INTEL_OUTPUT_DP_MST)
> > +		return;
> 
> NULL encoder should imo be caught in core. Type != DP_MST is impossible,
> if you're unsure make it into a BUG_ON for testing.


I don't get why (type != INTEL_OUTPUT_DP_MST) is impossible. Is that
because we have the implementation for atomic_release() only for MST
connectors? But, that is only for now.

-DK
> > +
> > +	intel_mst = enc_to_mst(encoder);
> > +	mgr = &intel_mst->primary->dp.mst_mgr;
> > +
> > +	topology_state = drm_atomic_get_mst_topology_state(conn_state->state,
> > +							   mgr);
> > +	if (IS_ERR(topology_state)) {
> > +		DRM_DEBUG_KMS("failed to create MST topology state %ld\n",
> > +				PTR_ERR(topology_state));
> > +		return;
> > +	}
> > +
> > +	drm_dp_atomic_release_vcpi_slots(topology_state, intel_connector->port);
> 
> I think it'd be great to merge this together into 1 helper that both gets
> the state and releases the vcpi, for less code in drivers.

Agreed.

> > +}
> > +
> >  static void intel_mst_disable_dp(struct intel_encoder *encoder,
> >  				 struct intel_crtc_state *old_crtc_state,
> >  				 struct drm_connector_state *old_conn_state)
> > @@ -401,6 +428,7 @@ static const struct drm_connector_helper_funcs intel_dp_mst_connector_helper_fun
> >  	.mode_valid = intel_dp_mst_mode_valid,
> >  	.atomic_best_encoder = intel_mst_atomic_best_encoder,
> >  	.best_encoder = intel_mst_best_encoder,
> > +	.atomic_release = intel_dp_mst_atomic_release,
> >  };
> >  
> >  static void intel_dp_mst_encoder_destroy(struct drm_encoder *encoder)
> > -- 
> > 2.7.4
> > 
>