Commit e3713738 authored by Imre Deak's avatar Imre Deak
Browse files

drm/i915/dp_mst: Force modeset CRTC if DSC toggling requires it 



Enabling / disabling DSC decompression in the branch device downstream
of the source may reset the whole branch device. To avoid this while the
streams are still active, force a modeset on all CRTC/ports connected to
this branch device.

v2:
- Check the CRTC state for each connector in the topology, instead of
  the CRTC being checked for a modeset requirement. (Ville)
- Add DocBook for the new function.
v3:
- Rebased on a change not to use
  intel_modeset_pipes_in_mask_early().

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com> (v1)
Signed-off-by: default avatarImre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231107001505.3370108-8-imre.deak@intel.com
parent 1e4bd5c1

drivers/gpu/drm/i915/display/intel_display.c

+3 −0
Original line number Diff line number Diff line
@@ -6481,6 +6481,9 @@ int intel_atomic_check(struct drm_device *dev, 
		if (!new_crtc_state->hw.enable || intel_crtc_needs_modeset(new_crtc_state))

			continue;



		if (intel_dp_mst_crtc_needs_modeset(state, crtc))

			intel_crtc_flag_modeset(new_crtc_state);



		if (intel_dp_mst_is_slave_trans(new_crtc_state)) {

			enum transcoder master = new_crtc_state->mst_master_transcoder;

drivers/gpu/drm/i915/display/intel_dp_mst.c

+88 −0
Original line number Diff line number Diff line
@@ -1628,3 +1628,91 @@ int intel_dp_mst_add_topology_state_for_crtc(struct intel_atomic_state *state, 


	return 0;

}



static struct intel_connector *

get_connector_in_state_for_crtc(struct intel_atomic_state *state,

				const struct intel_crtc *crtc)

{

	struct drm_connector_state *old_conn_state;

	struct drm_connector_state *new_conn_state;

	struct drm_connector *_connector;

	int i;



	for_each_oldnew_connector_in_state(&state->base, _connector,

					   old_conn_state, new_conn_state, i) {

		struct intel_connector *connector =

			to_intel_connector(_connector);



		if (old_conn_state->crtc == &crtc->base ||

		    new_conn_state->crtc == &crtc->base)

			return connector;

	}



	return NULL;

}



/**

 * intel_dp_mst_crtc_needs_modeset - check if changes in topology need to modeset the given CRTC

 * @state: atomic state

 * @crtc: CRTC for which to check the modeset requirement

 *

 * Check if any change in a MST topology requires a forced modeset on @crtc in

 * this topology. One such change is enabling/disabling the DSC decompression

 * state in the first branch device's UFP DPCD as required by one CRTC, while

 * the other @crtc in the same topology is still active, requiring a full modeset

 * on @crtc.

 */

bool intel_dp_mst_crtc_needs_modeset(struct intel_atomic_state *state,

				     struct intel_crtc *crtc)

{

	const struct intel_connector *crtc_connector;

	const struct drm_connector_state *conn_state;

	const struct drm_connector *_connector;

	int i;



	if (!intel_crtc_has_type(intel_atomic_get_new_crtc_state(state, crtc),

				 INTEL_OUTPUT_DP_MST))

		return false;



	crtc_connector = get_connector_in_state_for_crtc(state, crtc);



	if (!crtc_connector)

		/* None of the connectors in the topology needs modeset */

		return false;



	for_each_new_connector_in_state(&state->base, _connector, conn_state, i) {

		const struct intel_connector *connector =

			to_intel_connector(_connector);

		const struct intel_crtc_state *new_crtc_state;

		const struct intel_crtc_state *old_crtc_state;

		struct intel_crtc *crtc_iter;



		if (connector->mst_port != crtc_connector->mst_port ||

		    !conn_state->crtc)

			continue;



		crtc_iter = to_intel_crtc(conn_state->crtc);



		new_crtc_state = intel_atomic_get_new_crtc_state(state, crtc_iter);

		old_crtc_state = intel_atomic_get_old_crtc_state(state, crtc_iter);



		if (!intel_crtc_needs_modeset(new_crtc_state))

			continue;



		if (old_crtc_state->dsc.compression_enable ==

		    new_crtc_state->dsc.compression_enable)

			continue;

		/*

		 * Toggling the decompression flag because of this stream in

		 * the first downstream branch device's UFP DPCD may reset the

		 * whole branch device. To avoid the reset while other streams

		 * are also active modeset the whole MST topology in this

		 * case.

		 */

		if (connector->dp.dsc_decompression_aux ==

		    &connector->mst_port->aux)

			return true;

	}



	return false;

}

drivers/gpu/drm/i915/display/intel_dp_mst.h

+2 −0
Original line number Diff line number Diff line
@@ -22,5 +22,7 @@ bool intel_dp_mst_is_slave_trans(const struct intel_crtc_state *crtc_state); 
bool intel_dp_mst_source_support(struct intel_dp *intel_dp);

int intel_dp_mst_add_topology_state_for_crtc(struct intel_atomic_state *state,

					     struct intel_crtc *crtc);

bool intel_dp_mst_crtc_needs_modeset(struct intel_atomic_state *state,

				     struct intel_crtc *crtc);



#endif /* __INTEL_DP_MST_H__ */