On 12/16/2021 3:55 AM, Ilpo Järvinen wrote:
...

quoted

+	switch (reason) {
+	case EXCEPTION_HS_TIMEOUT:
+		dev_err(dev, "BOOT_HS_FAIL\n");
+		break;
+
+	case EXCEPTION_EVENT:
+		t7xx_fsm_broadcast_state(ctl, MD_STATE_EXCEPTION);
+		t7xx_md_exception_handshake(ctl->md);
+
+		cnt = 0;
+		while (cnt < FSM_MD_EX_REC_OK_TIMEOUT_MS / FSM_EVENT_POLL_INTERVAL_MS) {
+			if (kthread_should_stop())
+				return;
+
+			spin_lock_irqsave(&ctl->event_lock, flags);
+			event = list_first_entry_or_null(&ctl->event_queue,
+							 struct t7xx_fsm_event, entry);
+			if (event) {
+				if (event->event_id == FSM_EVENT_MD_EX) {
+					fsm_del_kf_event(event);
+				} else if (event->event_id == FSM_EVENT_MD_EX_REC_OK) {
+					rec_ok = true;
+					fsm_del_kf_event(event);
+				}
+			}
+
+			spin_unlock_irqrestore(&ctl->event_lock, flags);
+			if (rec_ok)
+				break;
+
+			cnt++;
+			/* Try again after 20ms */
+			msleep(FSM_EVENT_POLL_INTERVAL_MS);
+		}
+
+		cnt = 0;
+		while (cnt < FSM_MD_EX_PASS_TIMEOUT_MS / FSM_EVENT_POLL_INTERVAL_MS) {
+			if (kthread_should_stop())
+				return;
+
+			spin_lock_irqsave(&ctl->event_lock, flags);
+			event = list_first_entry_or_null(&ctl->event_queue,
+							 struct t7xx_fsm_event, entry);
+			if (event && event->event_id == FSM_EVENT_MD_EX_PASS) {
+				pass = true;
+				fsm_del_kf_event(event);
+			}
+
+			spin_unlock_irqrestore(&ctl->event_lock, flags);
+
+			if (pass)
+				break;
+			cnt++;
+			/* Try again after 20ms */
+			msleep(FSM_EVENT_POLL_INTERVAL_MS);
+		}

It hurts me a bit to see so much code duplication with only that one
extra if branch + if condition right-hand sides being different. It would
seem like something that could be solved with a helper taking those two
things as parameters.

I hope the ordering of FSM_EVENT_MD_EX, FSM_EVENT_MD_EX_REC_OK, and
FSM_EVENT_MD_EX_PASS is guaranteed by something. Otherwise, the event
being waited for might not become the first entry in the event_queue and
the loop just keeps waiting until timeout?

Ordering is guaranteed by the modem. Removing code duplication in the 
next iteration.

quoted

+void t7xx_fsm_clr_event(struct t7xx_fsm_ctl *ctl, enum t7xx_fsm_event_state event_id)
+{
+       struct device *dev = &ctl->md->t7xx_dev->pdev->dev;
+       struct t7xx_fsm_event *event, *evt_next;
+       unsigned long flags;
+
+       spin_lock_irqsave(&ctl->event_lock, flags);
+       list_for_each_entry_safe(event, evt_next, &ctl->event_queue, entry) {
+               dev_err(dev, "Unhandled event %d\n", event->event_id);
+
+               if (event->event_id == event_id)
+                       fsm_del_kf_event(event);
+       }

It seems that only events matching to event_id are removed from the
event_queue. Can that dev_err print the same event over and over again
(I'm assuming here multiple calls to t7xx_fsm_clr_event can occur) because
the other events still remaining in event_queue?

The purpose of this function is just to remove an event if present, it 
is not relevant if there

were other events in the list, so I'll remove the dev_err.