serial console, COM port not working -> [FILTER] ?

[Frederique Rijsdijk]

I'm setting up serial console access to our machines.

One of them isn't giving a login prompt, and I noticed a difference in
dmesg output:

> sio0: <16550A-compatible COM port> port 0x3f8-0x3ff irq 4 flags 0x10 on acpi0
> sio0: type 16550A
> sio0: [FILTER]

The last line I don't see on boxes where all is fine. My C reading isn't
that good, but I've found in /usr/src/sys/kern/subr_bus.c:

> bus_setup_intr(device_t dev, struct resource *r, int flags,
>     driver_filter_t filter, driver_intr_t handler, void *arg, void **cookiep)
> {
>         int error;
> 
>         if (dev->parent != NULL) {
>                 error = BUS_SETUP_INTR(dev->parent, dev, r, flags,
>                     filter, handler, arg, cookiep);
>                 if (error == 0) {
>                         if (handler != NULL && !(flags & INTR_MPSAFE))
>                                 device_printf(dev, "[GIANT-LOCKED]\n");
>                         if (bootverbose && (flags & INTR_MPSAFE))
>                                 device_printf(dev, "[MPSAFE]\n");
>                         if (filter != NULL) {
>                                 if (handler == NULL)
>                                         device_printf(dev, "[FILTER]\n");
>                                 else   
>                                         device_printf(dev, "[FILTER+ITHREAD]\n");
>                         } else
>                                 device_printf(dev, "[ITHREAD]\n");
>                 }
>         } else
>                 error = EINVAL;
>         return (error);
> }

But what does it mean?


Thanks,

-- Frederique