[PATCH v2 11/20] drm/i915/dp: Reprobe connector if getting/acking device IRQs fails

[Imre Deak <imre.deak@intel.com>]

From: Imre Deak <imre.deak@gmail.com>

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.

Signed-off-by: Imre Deak <imre.deak@gmail.com>
---
 drivers/gpu/drm/i915/display/intel_dp.c | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 3ac9458a2c7d0..613fb0cd08b78 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -5772,16 +5772,20 @@ 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)
+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;
 
-	drm_dp_dpcd_writeb(&intel_dp->aux, DP_DEVICE_SERVICE_IRQ_VECTOR, val);
+	if (!val)
+		return false;
+
+	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);
@@ -5791,6 +5795,8 @@ 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)
@@ -5855,8 +5861,11 @@ 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);
-- 
2.49.1