softdevice controller use

RE: softdevice controller use

protobits — Wed, 27 Jan 2021 02:20:40 GMT

Actually I see that the example code mostly does the same: it triggers event handling right after sending, by posting the same semaphore that is posted when the signal is received from MPSL:

static int cmd_handle(struct net_buf *cmd)
{
        BT_DBG("");

        int errcode = MULTITHREADING_LOCK_ACQUIRE();

        if (!errcode) {
                errcode = hci_internal_cmd_put(cmd->data);
                MULTITHREADING_LOCK_RELEASE();
        }
        if (errcode) {
                return errcode;
        }

        k_sem_give(&sem_recv);

        return 0;
}

and

void host_signal(void)
{
        /* Wake up the RX event/data thread */
        k_sem_give(&sem_recv);
}

It would be good if you could clarify as to why this is needed. In other words, what kind of events will trigger the signal and which will not. Also, I think that this should be better documented as it is not evident from the documentation.

RE: softdevice controller use

protobits — Wed, 27 Jan 2021 02:02:54 GMT

I continued testing by manually calling by sd_hci_signal() handler, which let me complete host layer initialization by receiving all "command complete" events that were being generated during setup. Once I started advertising I got the SWI5 interrupt.

I'm beginning to think that this signaling is not used for all HCI events or maybe there's some HCI command which triggers the signaling to start. Or maybe there's some issue in MPSL/SDC?

RE: softdevice controller use

protobits — Tue, 26 Jan 2021 18:49:52 GMT

Yes, that is part of normal NuttX boot. As I mentioned, I can manually trigger an interrupt (up_trigger_irq) and it will go to the handler as expected. The problems is that SDC does not seem to be interacting with MPSL so that MPSL itself triggers the IRQ.

RE: softdevice controller use

Sigurd — Tue, 26 Jan 2021 18:42:09 GMT

Do you know if up_irqinitialize() is being called somewhere in your project/code ?

RE: softdevice controller use

protobits — Mon, 25 Jan 2021 21:24:05 GMT

No, that handler is not called (even when I can manually verify that there's a pending HCI event). I understand that to trigger that call, mpsl should pend the configured interrupt (in this case, SWI5) from which I would call mpsl_low_priority_process(), but that interrupt is not triggered. Finally, If I call mpsl_low_priority_process() manually, the handler passed to sdc_enable() is not called either. So it would seem that mpsl is not aware that sdc has a pending HCI event.

RE: softdevice controller use

Sigurd — Mon, 25 Jan 2021 21:19:53 GMT

Hi,

[quote userid="92543" url="~/f/nordic-q-a/70843/softdevice-controller-use"] I don't receive SWI interrupt which would lead to signaling for available HCI EVT.[/quote]

The callback function you pass to sdc_enable() will be executed when HCI data or and HCI event is available. The callback will be executed in the same context as mpsl_low_priority_process.

From your code snippet, your callback function is named sdc_hci_signal(). Does sdc_hci_signal() execute/trigger when send the first HCI command?