drm/i915/dp: Reprobe connector if getting/acking device IRQs fails

An AUX access failure during HPD IRQ handling should be handled by
falling back to a full connector detection, ensure that if the failure
happens while reading/acking a device service IRQ.

v2: Document intel_dp_check_device_service_irq()'s return value.
    (Jani, Luca)

Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Luca Coelho <luciano.coelho@intel.com>
Reviewed-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patch.msgid.link/20260225164618.1261368-12-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 d63c3d69e9fcb2b4d44341ad04e09e647272e6a8..a39cfde1134c93b1b829524604f5c2ef58f876b9 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -5785,16 +5785,24 @@ void intel_dp_check_link_state(struct intel_dp *intel_dp)
        intel_encoder_link_check_queue_work(encoder, 0);
 }
 
-static void intel_dp_check_device_service_irq(struct intel_dp *intel_dp)
+/*
+ * Return %true if a full connector reprobe is required due to a failure while
+ * reading or acking the device service IRQs.
+ */
+static bool intel_dp_check_device_service_irq(struct intel_dp *intel_dp)
 {
        struct intel_display *display = to_intel_display(intel_dp);
        u8 val;
 
        if (drm_dp_dpcd_readb(&intel_dp->aux,
-                             DP_DEVICE_SERVICE_IRQ_VECTOR, &val) != 1 || !val)
-               return;
+                             DP_DEVICE_SERVICE_IRQ_VECTOR, &val) != 1)
+               return true;
+
+       if (!val)
+               return false;
 
-       drm_dp_dpcd_writeb(&intel_dp->aux, DP_DEVICE_SERVICE_IRQ_VECTOR, val);
+       if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_DEVICE_SERVICE_IRQ_VECTOR, val) != 1)
+               return true;
 
        if (val & DP_AUTOMATED_TEST_REQUEST)
                intel_dp_test_request(intel_dp);
@@ -5804,6 +5812,8 @@ static void intel_dp_check_device_service_irq(struct intel_dp *intel_dp)
 
        if (val & DP_SINK_SPECIFIC_IRQ)
                drm_dbg_kms(display->drm, "Sink specific irq unhandled\n");
+
+       return false;
 }
 
 static bool intel_dp_check_link_service_irq(struct intel_dp *intel_dp)
@@ -5868,8 +5878,11 @@ intel_dp_short_pulse(struct intel_dp *intel_dp)
                /* No need to proceed if we are going to do full detect */
                return false;
 
-       intel_dp_check_device_service_irq(intel_dp);
-       reprobe_needed = intel_dp_check_link_service_irq(intel_dp);
+       if (intel_dp_check_device_service_irq(intel_dp))
+               reprobe_needed = true;
+
+       if (intel_dp_check_link_service_irq(intel_dp))
+               reprobe_needed = true;
 
        /* Handle CEC interrupts, if any */
        drm_dp_cec_irq(&intel_dp->aux);