Re: [BUG] PCI/USB4: AMD Phoenix 1022:14ef runtime suspend prevents JHL9480 downstream enumeration

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

Hi,

On Fri, Sep 25, 2026 at 11:31:55AM +0000, Freeman Z wrote:
> Hi Mika, Alex and Mario,
> 
> I tested v7.3-rc4 with the following Ubuntu SAUCE patch from
> Chia-Lin Kao (AceLan) at Canonical:
> 
>     thunderbolt: Fix PCIe device enumeration with delayed rescan
> 
> Ubuntu SRU posting:
>     https://lists.ubuntu.com/archives/kernel-team/2026-April/166926.html
> 
> Launchpad:
>     https://bugs.launchpad.net/bugs/2139572
> 
> The Ubuntu posting says this was cherry-picked from the corresponding
> upstream submission:
> 
>     https://lore.kernel.org/lkml/20260121060857.237777-1-acelan.kao@canonical.com/T/#u
> 
> The patch schedules a delayed pci_rescan_bus() 300 ms after the
> Thunderbolt PCIe tunnel has been activated, to recover devices that
> pciehp did not enumerate.

Oh I remember that. It's a horrible hack that is never going to applied.

Based on this we now know why it "works" in Ubuntu. Thanks for finding it.

I think the real issue is that the PME is not propagated as it should,
either missing wake or something else but that's what the AMD folks can
hopefully help us to figure out.