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: Luca Coelho <[email protected]> Signed-off-by: Imre Deak <[email protected]> --- .../gpu/drm/i915/display/intel_display_types.h | 1 + drivers/gpu/drm/i915/display/intel_dp.c | 16 +++++++++++++++- 2 files changed, 16 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h index e8e4af03a6a6c..126682ecabec9 100644 --- a/drivers/gpu/drm/i915/display/intel_display_types.h +++ b/drivers/gpu/drm/i915/display/intel_display_types.h @@ -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]; diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index 5f5e0145cbb69..f7f02ce5d1a77 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -5543,7 +5543,14 @@ 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); - return err; + 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 @@ -5863,6 +5870,11 @@ 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)) { @@ -5888,6 +5900,8 @@ 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)) -- 2.49.1
