[LinuxBIOS] Tyan S2865 CK804 interrupt routing help needed

[Jeremy Jackson]

On Wed, 2007-05-16 at 11:49 -0700, yhlu wrote:
> PCI slot one has all
> > four interrupts working.
> >
> > What doesn't work yet is:
> > 1) PCI slots 2-4
> > -there doesn't seem to be any interrupts generated.  slot 2 and 4 can do
> > ifconfig up, but don't transmit or receive any packets.  slot 3 refuses
> > to ifconfig up.
> >
> > 2)firewire (it's on PCI bus, so it's probably related to 1) gets no
> > interrupts.  If the module is reloaded, dmesg fills the screen endlessly
> > and hard reset is required.
> 
> without schematic, that will need some try and test to figure out.

The Tyan S2865 User's Manual Revision 1.00 on page 31 "PCI IDSELs and
IRQ Assignments" isn't very helpful.   It looks like it's taken from a
dual-socket/multi-southbridge motherboard. Rev 1.03 is the same.

PCI slot 1 - all 4 PIRQ[ABCD] are working.  I used a multimeter to find
where these go on the other PCI slots 2-4, and for onboard Via VT6307
PCI firewire.

I have set mptables.c to match IRQs from working slot1 according to the
swizzle table I have discovered:

PCI Slot, IDSEL, PIRQA, PIRQB, PIRQC, PIRQD
ati rage xl, 21, ?, n/a, n/a, n/a
via firewire, 22, C, ?, n/a, n/a
1, 23, A, B, C, D
2, 24, D, A, B, C
3, 25, C, D, A, B
4, 26, B, C, D, A

Other than IDSEL and PIRQ traces, I can't think of any differences
between the PCI slots, and yet only slot 1 is working.  Maybe the
southbridge has some configuration for arbitration priority that's not
set by LinuxBIOS?

I will try and find a PCI card that generates interrupts, but doesn't
use bus mastering, as most NICs do, to try and furthur diagnose the
problem.

Jeremy