drm/i915/dp: Reprobe connector if getting/acking link service 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 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@intel.com>
Reviewed-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patch.msgid.link/20260225164618.1261368-13-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 a39cfde1134c93b1b829524604f5c2ef58f876b9..a240b7f17ac457997fd044cacc9ca504055ebbad 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -5816,6 +5816,11 @@ 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);
@@ -5826,12 +5831,15 @@ 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;