Re: Intel D2500CC motherboard and strange RS232/UART behavior

On 9 April 2013 23:28, Lev Serebryakov <lev_at_freebsd.org> wrote:
> 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.

.. surely it's solvable with a bit of ugliness?

Eg, looping over them until they all return "not handled" or you hit a
limit, or something equally ew.

.. assuming that it is broken in the first place, that is.



Adrian