Re: Intel D2500CC motherboard and strange RS232/UART behavior

From: Lev Serebryakov <lev_at_FreeBSD.org>
Date: Wed, 10 Apr 2013 00:42:29 +0400
Hello, John.
You wrote 10 апреля 2013 г., 0:08:09:

>> .. did we really break shared interrupt handling on ISA?
JB> When did it ever work?
  sio has special hacks to make it work, and in my experience, it
  worked around FreeBSD 4 (or even 3? I've started with 2.2.2, but it
  was later), when I had some systems with multiple internal ISA
  modems (does anybody remember word "FIDO" here?)

>> God, you made me remember ISA interrupt sharing. I thought the main
>> source of evilness is edge shared interrupts?
JB> Right, and ISA are edge and active-hi, so generally not shareable.
   As far as I remember, it is changeable. But I could be wrong here.

JB> Can you assign different interrupts via the BIOS somehow?
  I'll try. I could disable uart2 and 3 for sure, and then uart0 and
  uart1 will have unique standard (4 and 3) IRQ. I'll try it tomorrow.

-- 
// Black Lion AKA Lev Serebryakov <lev_at_FreeBSD.org>
Received on Tue Apr 09 2013 - 18:42:40 UTC

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