PING: Someone on the core team. (Modem Problem)

[Daniel Rudy]

At about the time of 2/15/2007 12:14 AM, Peter Jeremy stated the following:
> On 2007-Feb-14 00:27:36 -0800, Daniel Rudy <dr2867 at pacbell.net> wrote:
>> Changing the slot did help.  I moved it from slot 3 to slot 1.  But, now
>> it's dropping characters with a port speed of 57600, and I am also
>> getting irq overrun errors from the kernel too now.
> 
> This is not good.  Interrupt latency is a bit of a sore point but the
> FIFO trigger level is 8 bytes so getting SILO overflows implies a
> latency of >1.38msec.  Does sio4 report as [FAST] in the dmesg?
> 
> Unfortunately, there's no easy way to change the FIFO trigger level -
> you would need to patch the source code (look for FIFO_RX_MEDH in
> /usr/sys/dev/sio/sio.c if you want to go down this path).
> 
>>  With a port speed of 2400, I do not drop characters.
> 
> The FIFO is not enabled at speeds at or below 4800bps.
> 

I have tried several combinations of settings where the < 4800 was, I
even disabled the FIFO, but I still have the same problem: silo
overflows.  Is there a way for force the driver to attach as fast since
it's not doing it?

-- 
Daniel Rudy