Re: [REGRESSION 6.16] r8169 RTL8168h/8111h fails to probe — "Unable to change power state from D3cold to D0" — bisected to 4d4c10f763d7

On 6/17/26 01:32, Thorsten Leemhuis wrote:
> On 6/12/26 03:07, Josh Perry wrote:
>> #regzbot introduced: 4d4c10f763d7
>>
>> Since v6.16 one of two onboard RTL8168h/8111h NICs on this board fails
>> to probe on boot; the device drops to D3cold and the driver can't bring
>> it back:
> 
> FWIW, that commit is 4d4c10f763d780 ("PCI: Explicitly put devices into
> D0 when initializing") [v6.16-rc1] from Mario, who is already CCed, but
> looks like might be on holiday or something due to inactivity on the
> lists in the recent days. So it might take a few days before this moves on.
> 
> Josh, this is not my area of expertise, but there are two things I guess
> might be helpful:
> 
> * retry with 7.1
> * upload "dmesg" and "sudo lspci -vvv" output from working and broken
> kernels somewhere (like bugzilla.kernel.org).

Yes; please retry with mainline.  We already had multiple regressions 
from that commit fixed, so if you bisected down to this commit then it's 
plausible that there is already a fix.

> 
> Ciao, Thorsten
> 
>>    r8169 0000:02:00.0 eth0: RTL8168h/8111h, 00:2b:67:48:40:01, XID 541,
>> IRQ 137
>>    r8169 0000:04:00.0: Unable to change power state from D3cold to D0,
>> device inaccessible
>>    r8169 0000:04:00.0: Mem-Wr-Inval unavailable
>>    r8169 0000:04:00.0: error -EIO: PCI read failed
>>    r8169 0000:04:00.0: probe with driver r8169 failed with error -5
>>
>> The board has two identical RTL8168h NICs (both XID 541): 0000:02:00.0
>> and 0000:04:00.0. Only 04:00.0 fails — its sibling 02:00.0, on a
>> different root port, probes and works normally on the very same kernel
>> and boot. The failing NIC then does not appear (no enp4s0), taking the
>> machine's WAN offline. This strongly suggests the problem is port/
>> topology-specific rather than device- or driver-specific: the upstream
>> port behind 04:00.0 is placed in D3cold and the endpoint cannot be
>> resumed to D0.
>>
>> Hardware: RTL8168h/8111h, XID 541, PCI 04:00.0 (onboard 1GbE).
>> Platform: Lenovo ThinkCentre M90n-1 (11AHS0B200), BIOS M2AKT49A
>> (2026-03-25, latest available). Firmware is current, so this is not a
>> platform-firmware issue.
>>
>> Bisection: v6.15 good, v6.16 bad (verified by booting both). I then
>> reverted 4d4c10f763d7 ("PCI: Explicitly put devices into D0 when
>> initializing") together with its follow-up 907a7a2e5bf4 ("PCI/PM: Set up
>> runtime PM even for devices without PCI PM") on top of 6.16.7: the NIC
>> probes and links at 1Gbps/Full normally, with no workaround:
>>
>>    r8169 0000:04:00.0 eth1: RTL8168h/8111h, 00:2b:67:48:40:02, XID 541,
>> IRQ 138
>>    r8169 0000:04:00.0 enp4s0: Link is Up - 1Gbps/Full - flow control rx/tx
>>
>> Workaround: booting an unmodified v6.16+ kernel with pcie_port_pm=off
>> also restores the NIC, which is consistent with the upstream port being
>> placed in D3cold and the device failing to resume to D0 after the
>> explicit-D0 init change.
>>
>> The follow-up 907a7a2e5bf4 does not fix this resume case: v6.18.33 is
>> still affected (retested today on current firmware).
>>
>> Happy to test patches or provide full dmesg / lspci.
>>
>