Re: ohci1394 problem (MMIO broken) (was 2.6.25-rc6-git6: Reported regressions from 2.6.24)

[Ingo Molnar <mingo@elte.hu>]

* Ingo Molnar <mingo@elte.hu> wrote:

> > Modprobing either ohci1394 or firewire_ohci seems to lock up the 
> > system.
> 
> that's weird. If you do the modprobe from a VGA console and do a 
> 'dmesg -n 8', do you get any ioremap printk shortly before the hard 
> lockup?

basically, old ioremap did this:

[  162.485605] ACPI: PCI Interrupt 0000:0c:03.0[A] -> GSI 19 (level, low) -> IRQ 19
[  162.485695] ioremap: 00000000(00000800) => f8978000

the theory (fact?) was that the zero physical address there (the 
'00000000') was some 4GB+ address truncated down to 32-bits.

OTOH, before this system worked for you before, i start to suspect that 
ioremap is a red herring here and that it's the code that gets to that 
physical address (which is ioremap-ed) is at fault here.

the hard hang might be your southbridge totally dumbfounded by the host 
OS attempting to do an MMIO access to an above-4GB address?

so the question is - what physical address did that ioremap do in 2.6.24 
(which presumly had a working ohci1394, right?), and why did it change 
to something else in -git?

	Ingo