- From: Ian Abbott <abbotti_at_mev.co.uk>
- Date: Fri, 27 Jan 2006 17:31:13 +0000
On 27/01/06 16:14, Michael R. Head wrote:
> On Fri, 2006-01-27 at 15:47 +0000, Ian Abbott wrote:
>> My guess is that the driver is always reading 0xFFFF from the ADCCON
>> register that has the "ADC busy" bit. The ADCCON is in the same region
>> as the ADCDATA register, so I think the driver is reading 0xFFFF from
>> all registers in that region. (The digital I/O, counter timer and
>> interrupt control registers are in a separate region to the ADC and DAC
>> stuff.)
>>
>> It would be interesting to change the following line in amplc_pci230.c
>> to check this suspicion:
>>
>> rt_printk("timeout\n");
>>
>> becomes:
>>
>> rt_printk("timeout (adccon=%x)\n", status);
>>
>> If it prints "timeout (adccon=ffff)" then my suspicion is correct.
>
> Cool. I'll try that out. What would it mean if is reading that?
It just means it's having trouble reading (and presumably writing) the
I/O ports. Bad ports usually read all ones. 0xFFFF is not a valid value
for the ADCCON register, so reads that, something's definately wrong.
>>> 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?
>> ./inpn won't be using interrupts, but the other bug-fix for the
>> never-ending interrupts suggests that interrupts are getting through and
>> that the region containing the interrupt status and control registers is
>> at least partially working. The region containing the ADC and DAC
>> registers probably isn't working, but I don't know if that is due to the
>> PLX PCI9052 bridge chip on the card, the PCI-to-PCI bridge or something
>> else. The fact that you're having trouble with other cards lets us off
>> the hook a bit unless they are also using PLX chips!
>
> All the cards I am having trouble with are using PLX chips of different
> model numbers. I did try a regular netgear ethernet card last month and
> it worked in all the slots.
That's interesting as it suggests some problem with PLX chips. The most
recent PLX chips for this sort of application (the 9000 series chips)
are the 9030, 9056 and 9656 (the last one being for 64-bit applications)
so it would be interesting to see if any of those have the same trouble.
If you can get hold of a PCI230+ card from Amplicon to try out, it
uses the newer PLX PCI 9030 chip.
--
-=( Ian Abbott _at_ MEV Ltd. E-mail: <abbotti_at_mev.co.uk> )=-
-=( Tel: +44 (0)161 477 1898 FAX: +44 (0)161 718 3587 )=-
Received on 2006-01-27Z17:31:13