drm/i915/pxp: Add drm_dbgs for critical PXP events.

Debugging PXP issues can't even begin without understanding precedding
sequence of important events. Add drm_dbg into the most important PXP
events.

 v5 : - rebase.
 v4 : - rebase.
 v3 : - move gt_dbg to after mutex block in function
        i915_gsc_proxy_component_bind. (Vivaik)
 v2 : - remove __func__ since drm_dbg covers that (Jani).
      - add timeout dbg of the restart from front-end (Alan).

Signed-off-by: Alan Previn <alan.previn.teres.alexis@intel.com>
Reviewed-by: Vivaik Balasubrawmanian <vivaik.balasubrawmanian@intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231122191523.58379-1-alan.previn.teres.alexis@intel.com

Author: aalteres

drivers/gpu/drm/i915/gt/uc/intel_gsc_proxy.c

@@ -322,6 +322,7 @@ static int i915_gsc_proxy_component_bind(struct device *i915_kdev,
 	gsc->proxy.component = data;
 	gsc->proxy.component->mei_dev = mei_kdev;
 	mutex_unlock(&gsc->proxy.mutex);
+	gt_dbg(gt, "GSC proxy mei component bound\n");
 
 	return 0;
 }
@@ -342,6 +343,7 @@ static void i915_gsc_proxy_component_unbind(struct device *i915_kdev,
 	with_intel_runtime_pm(&i915->runtime_pm, wakeref)
 		intel_uncore_rmw(gt->uncore, HECI_H_CSR(MTL_GSC_HECI2_BASE),
 				 HECI_H_CSR_IE | HECI_H_CSR_RST, 0);
+	gt_dbg(gt, "GSC proxy mei component unbound\n");
 }
 
 static const struct component_ops i915_gsc_proxy_component_ops = {

drivers/gpu/drm/i915/pxp/intel_pxp.c

@@ -303,6 +303,8 @@ static int __pxp_global_teardown_final(struct intel_pxp *pxp)
 
 	if (!pxp->arb_is_valid)
 		return 0;
+
+	drm_dbg(&pxp->ctrl_gt->i915->drm, "PXP: teardown for suspend/fini");
 	/*
 	 * To ensure synchronous and coherent session teardown completion
 	 * in response to suspend or shutdown triggers, don't use a worker.
@@ -324,6 +326,8 @@ static int __pxp_global_teardown_restart(struct intel_pxp *pxp)
 
 	if (pxp->arb_is_valid)
 		return 0;
+
+	drm_dbg(&pxp->ctrl_gt->i915->drm, "PXP: teardown for restart");
 	/*
 	 * The arb-session is currently inactive and we are doing a reset and restart
 	 * due to a runtime event. Use the worker that was designed for this.
@@ -332,8 +336,11 @@ static int __pxp_global_teardown_restart(struct intel_pxp *pxp)
 
 	timeout = intel_pxp_get_backend_timeout_ms(pxp);
 
-	if (!wait_for_completion_timeout(&pxp->termination, msecs_to_jiffies(timeout)))
+	if (!wait_for_completion_timeout(&pxp->termination, msecs_to_jiffies(timeout))) {
+		drm_dbg(&pxp->ctrl_gt->i915->drm, "PXP: restart backend timed out (%d ms)",
+			timeout);
 		return -ETIMEDOUT;
+	}
 
 	return 0;
 }
@@ -414,10 +421,12 @@ int intel_pxp_start(struct intel_pxp *pxp)
 	int ret = 0;
 
 	ret = intel_pxp_get_readiness_status(pxp, PXP_READINESS_TIMEOUT);
-	if (ret < 0)
+	if (ret < 0) {
+		drm_dbg(&pxp->ctrl_gt->i915->drm, "PXP: tried but not-avail (%d)", ret);
 		return ret;
-	else if (ret > 1)
+	} else if (ret > 1) {
 		return -EIO; /* per UAPI spec, user may retry later */
+	}
 
 	mutex_lock(&pxp->arb_mutex);
 

drivers/gpu/drm/i915/pxp/intel_pxp_irq.c

@@ -40,11 +40,12 @@ void intel_pxp_irq_handler(struct intel_pxp *pxp, u16 iir)
 		   GEN12_DISPLAY_APP_TERMINATED_PER_FW_REQ_INTERRUPT)) {
 		/* immediately mark PXP as inactive on termination */
 		intel_pxp_mark_termination_in_progress(pxp);
-		pxp->session_events |= PXP_TERMINATION_REQUEST | PXP_INVAL_REQUIRED;
+		pxp->session_events |= PXP_TERMINATION_REQUEST | PXP_INVAL_REQUIRED |
+				       PXP_EVENT_TYPE_IRQ;
 	}
 
 	if (iir & GEN12_DISPLAY_STATE_RESET_COMPLETE_INTERRUPT)
-		pxp->session_events |= PXP_TERMINATION_COMPLETE;
+		pxp->session_events |= PXP_TERMINATION_COMPLETE | PXP_EVENT_TYPE_IRQ;
 
 	if (pxp->session_events)
 		queue_work(system_unbound_wq, &pxp->session_work);

drivers/gpu/drm/i915/pxp/intel_pxp_session.c

@@ -137,8 +137,10 @@ void intel_pxp_terminate(struct intel_pxp *pxp, bool post_invalidation_needs_res
 static void pxp_terminate_complete(struct intel_pxp *pxp)
 {
 	/* Re-create the arb session after teardown handle complete */
-	if (fetch_and_zero(&pxp->hw_state_invalidated))
+	if (fetch_and_zero(&pxp->hw_state_invalidated)) {
+		drm_dbg(&pxp->ctrl_gt->i915->drm, "PXP: creating arb_session after invalidation");
 		pxp_create_arb_session(pxp);
+	}
 
 	complete_all(&pxp->termination);
 }
@@ -157,6 +159,8 @@ static void pxp_session_work(struct work_struct *work)
 	if (!events)
 		return;
 
+	drm_dbg(&gt->i915->drm, "PXP: processing event-flags 0x%08x", events);
+
 	if (events & PXP_INVAL_REQUIRED)
 		intel_pxp_invalidate(pxp);
 

drivers/gpu/drm/i915/pxp/intel_pxp_types.h

@@ -124,6 +124,7 @@ struct intel_pxp {
 #define PXP_TERMINATION_REQUEST  BIT(0)
 #define PXP_TERMINATION_COMPLETE BIT(1)
 #define PXP_INVAL_REQUIRED       BIT(2)
+#define PXP_EVENT_TYPE_IRQ       BIT(3)
 };
 
 #endif /* __INTEL_PXP_TYPES_H__ */