[SRU][R][PATCH 14/22] drm/i915/dp: Reprobe connector if getting/acking link service IRQs fails

[Werner Sembach]

From: Imre Deak <imre.deak at intel.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 link service IRQ.

While at it add code comment documenting the return value of
intel_dp_check_link_service_irq().

v2: Docuement intel_dp_check_link_service_irq()'s return value. (Jani)

Cc: Jani Nikula <jani.nikula at intel.com>
Reviewed-by: Luca Coelho <luciano.coelho at intel.com>
Signed-off-by: Imre Deak <imre.deak at intel.com>
Link: https://patch.msgid.link/20260225164618.1261368-13-imre.deak@intel.com
Signed-off-by: Werner Sembach <wse at tuxedocomputers.com>
---
 drivers/gpu/drm/i915/display/intel_dp.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index f54abfa550513..68532d743f7fd 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -5695,6 +5695,11 @@ static bool intel_dp_check_device_service_irq(struct intel_dp *intel_dp)
 	return false;
 }
 
+/*
+ * Return %true if a full connector reprobe is required due to a failure while
+ * reading or acking the link service IRQs or if the reprobing is required
+ * after handling a link service IRQ event.
+ */
 static bool intel_dp_check_link_service_irq(struct intel_dp *intel_dp)
 {
 	struct intel_display *display = to_intel_display(intel_dp);
@@ -5705,12 +5710,15 @@ static bool intel_dp_check_link_service_irq(struct intel_dp *intel_dp)
 		return false;
 
 	if (drm_dp_dpcd_readb(&intel_dp->aux,
-			      DP_LINK_SERVICE_IRQ_VECTOR_ESI0, &val) != 1 || !val)
+			      DP_LINK_SERVICE_IRQ_VECTOR_ESI0, &val) != 1)
+		return true;
+
+	if (!val)
 		return false;
 
 	if (drm_dp_dpcd_writeb(&intel_dp->aux,
 			       DP_LINK_SERVICE_IRQ_VECTOR_ESI0, val) != 1)
-		return false;
+		return true;
 
 	if (val & RX_CAP_CHANGED)
 		reprobe_needed = true;
-- 
2.43.0