Re: Greetings. Having a FIFO overrun when my amplc_pci230 card is set on the other side of a PCI bridge

On Wed, 2006-01-25 at 16:27 +0000, Ian Abbott wrote: 
> On 25/01/2006 16:03, Michael R. Head wrote:
> > On Wed, 2006-01-25 at 13:18 +0000, Ian Abbott wrote:
> > 
> >>On 24/01/06 19:21, Michael R. Head wrote:
> >>
> >>>I've discovered that the card was (and is) _not_ working properly when
> >>>it is on the main PCI bus. When I run the inp or inpn tests, I get
> >>>'timeout' printed on the console and in dmesg. I don't get this when the
> >>>card is on the other side of the PCI bridge. It appears the problem was
> >>>more subtle than I first though.
> >>
> >>It seems the test that checks the ADC busy flag is inverted.  The 
> >>attached patch should fix it.
> > 
> > Damn... I'll try this out today. But I'm guessing this means that I will
> > stop getting timeouts on the primary bus and start getting timeouts on
> > the expansion bus again...
> 
> I'm hoping it will work on both unless there's something seriously 
> strange going on!

Hmm... it is as I feared. It now works on the main PCI bus, but I get a
bunch of timeouts when the card is on the expansion bus. What's more, I
don't think it was working properly before. It seems your patches should
be combined and committed.

Here are the various results I get running inpn from comedilib:

Without this new patch, on the main PCI bus: 

[hwtester_at_host demo]$ ./inpn
0: 656968 328484 164242 82121 328489 164245 82122.3
1: 656968 328484 164242 82121 328489 164245 82122.3
2: 656968 328484 164242 82121 328489 164245 82122.3
3: 656968 328484 164242 82121 328489 164245 82122.3
4: 656968 328484 164242 82121 328489 164245 82122.3
5: 656968 328484 164242 0.000915751 5.00366 2.50183 1.25092
6: 0.00732601 0.003663 0.0018315 0.000915751 5.00366 2.50183 1.25092
7: 0.00732601 0.003663 0.0018315 0.000915751 5.00366 2.50183 1.25092
8: 0.00732601 0.003663 0.0018315 0.000915751 5.00366 2.50183 1.25092
9: 0.00732601 0.003663 0.0018315 0.000915751 5.00366 2.50183 1.25092
10: 0.00732601 0.003663 0.0018315 0.000915751 5.00366 2.50183 1.25092
11: 0.00732601 0.003663 -0.0177045 -0.00885226 4.96459 2.4823 1.24115
12: -0.0708181 -0.035409 -0.0177045 -0.00885226 4.96459 0.763126 0.381563
13: -6.9475 -3.47375 -1.73687 -0.868437 1.52625 0.763126 0.381563
14: -6.9475 -3.47375 -1.73687 -0.868437 1.52625 0.763126 0.381563
15: -6.9475 -3.47375 -1.73687 -0.868437 1.52625 0.763126 0.381563

The numbers above vary, but this particular run gave a good variety of
the values. If I run dmesg, I see the timeout message printed many times
over. If run it from a text console (outside of X), I get all the
timeouts printed inline with the output (as you might imagine for printk
messages).

Here is what I get on the expansion PCI bus:
[hwtester_at_host demo]$ ./inpn
0: -0.002442 -0.001221 -0.000610501 -0.00030525 nan nan nan
1: -0.002442 -0.001221 -0.000610501 -0.00030525 nan nan nan
2: -0.002442 -0.001221 -0.000610501 -0.00030525 nan nan nan
3: -0.002442 -0.001221 -0.000610501 -0.00030525 nan nan nan
4: -0.002442 -0.001221 -0.000610501 -0.00030525 nan nan nan
5: -0.002442 -0.001221 -0.000610501 -0.00030525 nan nan nan
6: -0.002442 -0.001221 -0.000610501 -0.00030525 nan nan nan
7: -0.002442 -0.001221 -0.000610501 -0.00030525 nan nan nan
8: -0.002442 -0.001221 -0.000610501 -0.00030525 nan nan nan
9: -0.002442 -0.001221 -0.000610501 -0.00030525 nan nan nan
10: -0.002442 -0.001221 -0.000610501 -0.00030525 nan nan nan
11: -0.002442 -0.001221 -0.000610501 -0.00030525 nan nan nan
12: -0.002442 -0.001221 -0.000610501 -0.00030525 nan nan nan
13: -0.002442 -0.001221 -0.000610501 -0.00030525 nan nan nan
14: -0.002442 -0.001221 -0.000610501 -0.00030525 nan nan nan
15: -0.002442 -0.001221 -0.000610501 -0.00030525 nan nan nan

Those numbers are always the same.

Now, here are the results with your new patch:

card on main PCI bus:
[hwtester_at_host demo]$ ./inpn
0: -4.98901 -0.199023 -0.0873016 -0.0363248 1.52137 nan nan
1: -5.62882 -0.860806 -0.468254 -0.249389 1.40415 nan nan
2: -5.04274 -0.474969 -0.214286 -0.0973748 1.49206 nan nan
3: -5.6337 -0.86569 -0.471917 -0.251832 1.35531 nan nan
4: -5.0525 -0.465201 -0.202076 -0.0906593 1.46276 nan nan
5: -5.61416 -0.868132 -0.452381 -0.240232 1.40659 nan nan
6: -5.06227 -0.506716 -0.230159 -0.106532 1.48718 nan nan
7: -5.55067 -0.868132 -0.449939 -0.227411 1.37485 nan nan
8: -5.04762 -0.357753 -0.154457 -0.0699023 1.50672 nan nan
9: -5.62393 -0.82906 -0.434066 -0.235348 1.41148 nan nan
10: -4.9304 -0.433455 -0.197192 -0.0912698 1.45055 nan nan
11: -5.6044 -0.863248 -0.459707 -0.243895 1.41148 nan nan
12: -5.0525 -0.555556 -0.260684 -0.118742 nan nan nan
13: -1.81441 -0.821734 -0.447497 -0.245726 1.39683 nan nan
14: -5.03297 -0.504274 -0.23138 -0.108364 1.48962 nan nan
15: -4.59341 -0.836386 -0.459707 -0.266484 1.37973 nan nan

Which looks right. Hurray!

And here's the card on the secondary PCI bus:
[hwtester_at_csi-lear-1 demo]$ ./inpn
0: 656968 328484 164242 82121 328489 164245 82122.3
1: 656968 328484 164242 82121 328489 164245 82122.3
2: 656968 328484 164242 82121 328489 164245 82122.3
3: 656968 328484 164242 82121 328489 164245 82122.3
4: 656968 328484 164242 82121 328489 164245 82122.3
5: 656968 328484 164242 82121 328489 164245 82122.3
6: 656968 328484 164242 82121 328489 164245 82122.3
7: 656968 328484 164242 82121 328489 164245 82122.3
8: 656968 328484 164242 82121 328489 164245 82122.3
9: 656968 328484 164242 82121 328489 164245 82122.3
10: 656968 328484 164242 82121 328489 164245 82122.3
11: 656968 328484 164242 82121 328489 164245 82122.3
12: 656968 328484 164242 82121 328489 164245 82122.3
13: 656968 328484 164242 82121 328489 164245 82122.3
14: 656968 328484 164242 82121 328489 164245 82122.3
15: 656968 328484 164242 82121 328489 164245 82122.3

And when I check dmesg, I get the timeouts.

I'm finding trouble with other PCI cards on the expansion, so it could
be a chipset issue or a general linux problem. If you can make an
educated guess as to what's causing the timeout across the PCI bridge,
I'd appreciate it. Do you think interrupts are simply not being
propagated? Maybe I/O or memory port data isn't getting to the card?

Either way, thanks for looking in to this.

mike

-- 
Michael R. Head <burner_at_suppressingfire.org>
GPG: http://www.suppressingfire.org/~burner/gpg.key.txt [0x4C9DA1D0]