On Wed, Jun 27, 2012 at 7:32 AM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote:
>> I do still plan to work on bisecting this.
>
> Can you also attach a dmesg log from a current kernel, e.g., 3.4 or
> newer? We now print a lot more information during PCI enumeration.
>
> But I guess the problem is that 2.6.26 finds devices in domains 1 and
> 2, while 2.6.32 does not. I think MMCONFIG is the only config access
> method we have for domains other than 0. That suggests that MMCONFIG
> used to work but doesn't any more. The dmesg logs claim that we're
> not using MMCONFIG in either 2.6.26 or 2.6.32 though, so I don't know
> why we found anything in 2.6.26.
in short: the bios is broken, it return wrong segment in DSDT.
in both case, only pci_conf1 is used. CPU is not new enough.
after comparing the code 2.6.26 and 2.6.32. 2.6.26 is not checking
seg in pci_conf1_read. but 2.6.32 check that...
2.6.26:
static int pci_conf1_read(unsigned int seg, unsigned int bus,
unsigned int devfn, int reg, int len, u32 *value)
{
unsigned long flags;
if ((bus > 255) || (devfn > 255) || (reg > 255)) {
*value = -1;
return -EINVAL;
}
2.6.32
20 static int pci_conf1_read(unsigned int seg, unsigned int bus,
21 unsigned int devfn, int reg, int len, u32 *value)
22 {
23 unsigned long flags;
24
25 if (seg || (bus > 255) || (devfn > 255) || (reg > 4095)) {
26 *value = -1;
27 return -EINVAL;
28 }
so it happens to work on 2.6.26.
please get to get new BIOS from your vendor.
or you need to override your DSDT.
Thanks
Yinghai
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