drm/i915/dp: Handle the RX_CAP_CHANGED HPD IRQ

Handle the RX_CAP_CHANGED IRQ, which a sink can use to indicate a DPRX
capability change without disconnecting and reconnecting itself (i.e.
through a short vs. long HPD pulse). Handle the IRQ by doing a full
connector detection.

Reviewed-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patch.msgid.link/20260225164618.1261368-6-imre.deak@intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 2e7a4df48afa7ebd3b20f31d868609e101ca7f84..966e652e38d2dae39a349735ff0b3bf123892cc6 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -5491,7 +5491,7 @@ intel_dp_check_mst_status(struct intel_dp *intel_dp)
 
                drm_dbg_kms(display->drm, "DPRX ESI: %4ph\n", esi);
 
-               ack[3] |= esi[3] & (LINK_STATUS_CHANGED | DP_TUNNELING_IRQ);
+               ack[3] |= esi[3] & (RX_CAP_CHANGED | LINK_STATUS_CHANGED | DP_TUNNELING_IRQ);
 
                intel_dp_mst_hpd_irq(intel_dp, esi, ack);
 
@@ -5504,6 +5504,9 @@ intel_dp_check_mst_status(struct intel_dp *intel_dp)
                if (ack[1] & (DP_DOWN_REP_MSG_RDY | DP_UP_REQ_MSG_RDY))
                        drm_dp_mst_hpd_irq_send_new_request(&intel_dp->mst.mgr);
 
+               if (ack[3] & RX_CAP_CHANGED)
+                       reprobe_needed = true;
+
                if ((ack[3] & LINK_STATUS_CHANGED) || intel_dp->link.force_retrain)
                        intel_dp_check_link_state(intel_dp);
 
@@ -5816,6 +5819,9 @@ static bool intel_dp_check_link_service_irq(struct intel_dp *intel_dp)
                               DP_LINK_SERVICE_IRQ_VECTOR_ESI0, val) != 1)
                return false;
 
+       if (val & RX_CAP_CHANGED)
+               reprobe_needed = true;
+
        if (val & HDMI_LINK_STATUS_CHANGED)
                intel_dp_handle_hdmi_link_status_change(intel_dp);