1 files changed, 37 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index e0ff9085fd86..58c827b52a29 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1776,6 +1776,27 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
         return false;
 }
 
+static bool
+intel_dp_get_sink_irq(struct intel_dp *intel_dp, u8 *sink_irq_vector)
+{
+        int ret;
+
+        ret = intel_dp_aux_native_read_retry(intel_dp,
+                                             DP_DEVICE_SERVICE_IRQ_VECTOR,
+                                             sink_irq_vector, 1);
+        if (!ret)
+                return false;
+
+        return true;
+}
+
+static void
+intel_dp_handle_test_request(struct intel_dp *intel_dp)
+{
+        /* NAK by default */
+        intel_dp_aux_native_write_1(intel_dp, DP_TEST_RESPONSE, DP_TEST_ACK);
+}
+
 /*
  * According to DP spec
  * 5.1.2:
@@ -1788,6 +1809,8 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
 static void
 intel_dp_check_link_status(struct intel_dp *intel_dp)
 {
+        u8 sink_irq_vector;
+
         if (intel_dp->dpms_mode != DRM_MODE_DPMS_ON)
                 return;
 
@@ -1806,6 +1829,20 @@ intel_dp_check_link_status(struct intel_dp *intel_dp)
                 return;
         }
 
+        /* Try to read the source of the interrupt */
+        if (intel_dp->dpcd[DP_DPCD_REV] >= 0x11 &&
+            intel_dp_get_sink_irq(intel_dp, &sink_irq_vector)) {
+                /* Clear interrupt source */
+                intel_dp_aux_native_write_1(intel_dp,
+                                            DP_DEVICE_SERVICE_IRQ_VECTOR,
+                                            sink_irq_vector);
+
+                if (sink_irq_vector & DP_AUTOMATED_TEST_REQUEST)
+                        intel_dp_handle_test_request(intel_dp);
+                if (sink_irq_vector & (DP_CP_IRQ | DP_SINK_SPECIFIC_IRQ))
+                        DRM_DEBUG_DRIVER("CP or sink specific irq unhandled\n");
+        }
+
         if (!intel_channel_eq_ok(intel_dp)) {
                 DRM_DEBUG_KMS("%s: channel EQ not ok, retraining\n",
                               drm_get_encoder_name(&intel_dp->base.base));