Re: [PATCH net-next v3 02/12] net: wwan: t7xx: Add core components

["Martinez, Ricardo" <ricardo.martinez@xxxxxxxxxxxxxxx>]

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

> > +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.