Re: [PATCH 00/24] Thunderbolt security levels and NVM firmware upgrade

[Mika Westerberg <mika.westerberg@linux.intel.com>]

On Fri, May 19, 2017 at 08:19:48PM +0300, Mika Westerberg wrote:
> These two I've seen before.
> 
> > [    7.428503] pcieport 0000:02:02.0: PCI bridge to [bus 39]
> > [    7.428512] pcieport 0000:02:02.0:   bridge window [mem 0xd9f00000-0xd9ffffff]
> > [    7.428519] pci_bus 0000:39: [bus 39] partially hidden behind bridge 0000:02 [bus 02-05]
> 
> And this.
> 
> It happens occasionally when you reboot the machine when a device is
> connected but seems to be dependent on the BIOS version. Since it is the
> BIOS who is supposed to enumerated these devices, I suspect that it is
> either problem in BIOS or our PCI enumeration code does something wrong.

I tried on Intel Skull Canyon NUC so that I downgraded the NVM firmware
from 25 to 18. With that I see the exactly same issue. Upgrading it back
to 25 seems to fix it.

Even with version 18 if I plug devices after boot or if the machine is
completely shut down from power button with devices connected, it works.
The problem happens only when the machine is warn booted.

However, since I'm able to reproduce this - I'll try to investigate what
might be the root cause.