Commit a6d89d46 authored by Imre Deak's avatar Imre Deak
Browse files

drm/i915/dp: Handle the DOWNSTREAM_PORT_STATUS_CHANGED event 



Handle the DOWNSTREAM_PORT_STATUS_CHANGED event a branch device can use
to indicate the state change of a DFP connector on the branch device.
The event is signaled in the DP_LANE_ALIGN_STATUS_UPDATED DPCD register
setting a clear-on-read flag and triggering an HPD IRQ. Accordingly keep
a cached version of the flag, updating it whenever
DP_LANE_ALIGN_STATUS_UPDATED is read. Schedule a full connector
detection from the HPD IRQ handler if the cached flag is set and clear
the cached flag at the start of detection.

Reviewed-by: default avatarLuca Coelho <luciano.coelho@intel.com>
Signed-off-by: default avatarImre Deak <imre.deak@intel.com>
Link: https://patch.msgid.link/20260225164618.1261368-7-imre.deak@intel.com
parent e55791f5

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

+1 −0
Original line number Diff line number Diff line
@@ -1796,6 +1796,7 @@ struct intel_dp { 
	int link_rate;

	u8 lane_count;

	u8 sink_count;

	bool downstream_port_changed;

	bool needs_modeset_retry;

	bool use_max_params;

	u8 dpcd[DP_RECEIVER_CAP_SIZE];

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

+15 −1
Original line number Diff line number Diff line
@@ -5556,7 +5556,14 @@ intel_dp_read_link_status(struct intel_dp *intel_dp, u8 link_status[DP_LINK_STAT 
		err = drm_dp_dpcd_read_phy_link_status(&intel_dp->aux, DP_PHY_DPRX,

						       link_status);



	if (err)

		return err;



	if (link_status[DP_LANE_ALIGN_STATUS_UPDATED - DP_LANE0_1_STATUS] &

	    DP_DOWNSTREAM_PORT_STATUS_CHANGED)

		WRITE_ONCE(intel_dp->downstream_port_changed, true);



	return 0;

}



static bool
@@ -5876,6 +5883,11 @@ intel_dp_short_pulse(struct intel_dp *intel_dp) 


	intel_dp_check_link_state(intel_dp);



	if (READ_ONCE(intel_dp->downstream_port_changed)) {

		WRITE_ONCE(intel_dp->downstream_port_changed, false);

		reprobe_needed = true;

	}



	intel_psr_short_pulse(intel_dp);



	if (intel_alpm_get_error(intel_dp)) {
@@ -5901,6 +5913,8 @@ intel_dp_detect_dpcd(struct intel_dp *intel_dp) 
	if (drm_WARN_ON(display->drm, intel_dp_is_edp(intel_dp)))

		return connector_status_connected;



	WRITE_ONCE(intel_dp->downstream_port_changed, false);



	intel_lspcon_resume(dig_port);



	if (!intel_dp_get_dpcd(intel_dp))