drm/i915/dp: Return early if getting/acking device service IRQs fails

If getting/acking the device service IRQs fail, the short HPD handler
should bail out, falling back to a full connector detection as in case
of any AUX access failures during the HPD handling. Do this by
separating the getting/acking and handling steps of the IRQs.

Reviewed-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patch.msgid.link/20260225164618.1261368-14-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 a240b7f17ac457997fd044cacc9ca504055ebbad..2a659977d775520e4a62a49db22851476a7e08a4 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -5789,31 +5789,39 @@ void intel_dp_check_link_state(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)
+static bool intel_dp_get_and_ack_device_service_irq(struct intel_dp *intel_dp, u8 *irq_mask)
 {
-       struct intel_display *display = to_intel_display(intel_dp);
        u8 val;
 
+       *irq_mask = 0;
+
        if (drm_dp_dpcd_readb(&intel_dp->aux,
                              DP_DEVICE_SERVICE_IRQ_VECTOR, &val) != 1)
-               return true;
+               return false;
 
        if (!val)
-               return false;
+               return true;
 
        if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_DEVICE_SERVICE_IRQ_VECTOR, val) != 1)
-               return true;
+               return false;
+
+       *irq_mask = val;
+
+       return true;
+}
+
+static void intel_dp_handle_device_service_irq(struct intel_dp *intel_dp, u8 irq_mask)
+{
+       struct intel_display *display = to_intel_display(intel_dp);
 
-       if (val & DP_AUTOMATED_TEST_REQUEST)
+       if (irq_mask & DP_AUTOMATED_TEST_REQUEST)
                intel_dp_test_request(intel_dp);
 
-       if (val & DP_CP_IRQ)
+       if (irq_mask & DP_CP_IRQ)
                intel_hdcp_handle_cp_irq(intel_dp->attached_connector);
 
-       if (val & DP_SINK_SPECIFIC_IRQ)
+       if (irq_mask & DP_SINK_SPECIFIC_IRQ)
                drm_dbg_kms(display->drm, "Sink specific irq unhandled\n");
-
-       return false;
 }
 
 /*
@@ -5872,6 +5880,7 @@ static bool
 intel_dp_short_pulse(struct intel_dp *intel_dp)
 {
        bool reprobe_needed = false;
+       u8 irq_mask;
 
        intel_dp_test_reset(intel_dp);
 
@@ -5886,8 +5895,10 @@ intel_dp_short_pulse(struct intel_dp *intel_dp)
                /* No need to proceed if we are going to do full detect */
                return false;
 
-       if (intel_dp_check_device_service_irq(intel_dp))
-               reprobe_needed = true;
+       if (!intel_dp_get_and_ack_device_service_irq(intel_dp, &irq_mask))
+               return false;
+
+       intel_dp_handle_device_service_irq(intel_dp, irq_mask);
 
        if (intel_dp_check_link_service_irq(intel_dp))
                reprobe_needed = true;