Shooting trouble on a PCI bus hang

[Warner Losh]

On Jun 20, 2011, at 6:49 AM, John Baldwin wrote:

> On Sunday, June 19, 2011 12:35:49 pm Ansar Mohammed wrote:
>> I appreciate that. The system works fine with NetBSD, LInux and Windows XP,
>> so I doubt its hardware.
>> 
>> Interesting though that OpenBSD has the same issue.
>> 
>> A question about the debug kernel load process: as it hangs on *
>> pci_print_verbose* in pci.c, can I deduce that this is the exact code
>> segment that is the issue?
> 
> Well, if that was the last device on the bus it might be in a device driver
> probe routine.  You can try adding more printfs to device_probe(), etc. to 
> output each driver name as it probes each device perhaps.

We've also had problems with interrupt storms after the drivers have all probed, and people blame the last printf :)

It sounds, however, with the OpenBSD datapoint that something is being initialized bogusly, perhaps tripping over an erratum that the other systems avoid or have specific code to work around.

Warner