Intel D2500CC motherboard and strange RS232/UART behavior
Lev Serebryakov
lev at FreeBSD.org
Wed Apr 10 06:28:44 UTC 2013
Hello, John.
You wrote 10 апреля 2013 г., 0:58:22:
>> Problem is, that every uart device now is independent from each
>> other in good "OOP" style, and it looks like interrupt sharing we
>> need one interrupt handler per irq (not per device), which will now
>> about several UARTs. Something like "multiport" device, bot not
>> exactly.
JB> No, the interrupt code itself will handle shared interrupts (it will
JB> call all handlers). I think in practice that uart is setting
And what will happen, if there is two UARTs asserting interrupt in
same time? First one returns "FILTER_HANDLED", will second handler be
called?
ISA interrupt sharing IS NOT so simple. sio contains a lot of
obscure code to work.
JB> INTR_EXCL or some such and/or uart doesn't set RF_SHAREABLE when
JB> allocating the IRQ. It is probably the latter. You could try just
JB> adding RF_SHAREABLE to the bus_alloc_resource_any() for the IRQ to
JB> uart and see if that fixes it.
sc->sc_ires = bus_alloc_resource_any(dev, SYS_RES_IRQ, &sc->sc_irid,
RF_ACTIVE | RF_SHAREABLE);
It is here.
--
// Black Lion AKA Lev Serebryakov <lev at FreeBSD.org>
More information about the freebsd-current
mailing list