Re: ACPI regression? Was Re: Ethernet chip disappeared from lspci

[Bjorn Helgaas]

[+cc linux-pci]

Hi Boszormenyi,

On Sun, Jun 21, 2015 at 5:34 AM, Boszormenyi Zoltan <zboszor@xxxxx> wrote:
> Hi,
>
> please, cc me, I am not subscribed to lkml.
>
>> Hi,
>>
>> [lkml.org still broken --> no accurate mail header info possible...]
>>
>> Just to ask the obvious:
>> I assume using /sys/bus/pci/rescan does not help once it's broken?
>> (since the machine comes up empty at initial-boot scan, too)
>
> I will try it, too, but I am not sure it would work.
>
> Currently I can't test it because the last time I completely discharged
> the battery. I also disconnected it to be able to get the realtek chip back
> immediately for faster testing. Now, that I have reconnected the battery,
> I need to wait for it to be charged somewhat to be able to reproduce
> losing the network chip.
>
>> Also, you could try diffing lspci -vvxxx -s.... output
>> of working vs. "distorting" kernel version - perhaps some register setup
>> has been changed (e.g. due to power management improvements or some such),
>> which may encourage the card
>> to get a problematic/corrupt state.
>
> I attached a tarball that contains lspci -vvxxx for
> - all devices / only the network chip
> - before / after "modprobe r8169"
> - for all 3 kernel versions tested.
>
> I figured out that if I type the modprobe and lspci in the same command line,
> I can get diagnostics out of the machine, after all.
>
> It's not just the Realtek chip that has changed parameters.
>
> (Vague idea) I noticed that some devices have changed like this:
>
> -       Memory behind bridge: 80000000-801fffff
> -       Prefetchable memory behind bridge: 0000000080200000-00000000803fffff
> +       Memory behind bridge: ff000000-ff1fffff
> +       Prefetchable memory behind bridge: 00000000ff200000-00000000ff3fffff
>
> Can't this cause a problem? E.g. programming the bridge with an address range
> that the bridge doesn't actually support?

This worked in v3.18.16, but not in v4.0.5 or v4.1.0-rc8.  You
attached a v4.1.0-rc8 dmesg log earlier.  Would you mind collecting a
v3.18.16 dmesg log, so we can compare them?

These (from the v4.1.0-rc8 dmesg) look wrong, but I'll have to look at
the code to see what might be going on:

  acpi PNP0A08:00: host bridge window expanded to [mem
0x00000000-0xffffffff window]; [mem 0x00000000-0xffffffff window]
ignored
  pci 0000:00:1c.1: can't claim BAR 15 [mem 0xfdf00000-0xfdffffff
64bit pref]: address conflict with PCI Bus 0000:00 [mem
0xf0000000-0xfed8ffff window]

Bjorn
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