Re: [REGRESSION] Intel Wireless adapter is not detected until suspending to RAM and resuming

["Mario Limonciello (AMD) (kernel.org)" <superm1@kernel.org>]

On 10/20/2025 11:37 AM, Mario Limonciello (AMD) (kernel.org) wrote:
> 
> 
> On 10/20/2025 7:56 AM, Adrià Vilanova Martínez wrote:
>> On Sun, Oct 19, 2025 at 07:25:08PM -0500, Mario Limonciello wrote:
>>> Thanks, knowing that pcie_aspm=off helps I think we should compare 
>>> output
>>> for:
>>>
>>> # sudo lspci -vvnn
>>
>> Sure, I'm attaching the outputs of this command for all the scenarios.
>> There are some differences, so it seems promising.
>>
> 
> Surprisingly there is nothing different about ASPM though.  It's all 
> PCI-PM differences.
> 
> Looking at your log again I noticed this from the bridge:
> 
> pcieport 0000:00:1c.0: pciehp: Slot(0): Card not present
> pcieport 0000:00:1c.0: pciehp: Slot(0): Card present
> pcieport 0000:00:1c.0: pciehp: Slot(0): Link Up
> ...
> pcieport 0000:00:1c.0: pciehp: Slot(0): No device found
> ...
> (suspend)
> ...
> pcieport 0000:00:1c.0: pciehp: Slot(0): Card present
> pcieport 0000:00:1c.0: pciehp: Slot(0): Link Up
> 
> 
>> I'm building the Kernel on the following commits:
>>
>> - "Kernel without 4d4c10f763 and 907a7a2e5b": 1c64efcb08, applying on
>> top reverts for these 2 commits. [locally compiled version
>> 6.18.0-rc1-local-reverted-pci-issues-00351-gbbaff7ff47dd]
>> - "Kernel with 4d4c10f763 and 907a7a2e5b": 1c64efcb08 (last commit I
>> pulled from mainline last week). [locally compiled version ???]
>>
>>> In the following cases (all without pcie_aspm=off):
>>>
>>> 1) At bootup; a kernel without 4d4c10f763 and 907a7a2e5b
>>
>> See 01_lspci_bootup_without_4d4c10f763_907a7a2e5b.txt
>>
> 
> OK so the bridge at 00:1c.0:
> L1SubCtl1: PCI-PM_L1.2+ PCI-PM_L1.1+ ASPM_L1.2- ASPM_L1.1-
> 
> 01:00.0 is present
> 
>>> 2) At bootup; a kernel with 4d4c10f763 and 907a7a2e5b
>>
>> See 02_lspci_bootup_with_4d4c10f763_907a7a2e5b.txt
>>
> 
> OK so the bridge at 00:1c.0:
> L1SubCtl1: PCI-PM_L1.2- PCI-PM_L1.1- ASPM_L1.2- ASPM_L1.1-
> 
> 01:00.0 is NOT present
> 
>>> 3) After suspend/resume; a kernel without 4d4c10f763 and 907a7a2e5b4
>>
>> See 03_lspci_after_suspend_resume_without_4d4c10f763_907a7a2e5b.txt
>>
> 
> OK so the bridge at 00:1c.0:
> L1SubCtl1: PCI-PM_L1.2+ PCI-PM_L1.1+ ASPM_L1.2- ASPM_L1.1-
> 
> 01:00.0 is present
> 
>>> 4) After suspend/resume; a kernel with 4d4c10f763 and 907a7a2e5b
>>
>> See 04_lspci_after_suspend_resume_with_4d4c10f763_907a7a2e5b.txt
>>
> 
> OK so the bridge at 00:1c.0:
> L1SubCtl1: PCI-PM_L1.2- PCI-PM_L1.1- ASPM_L1.2- ASPM_L1.1-
> 
> 01:00.0 is present
> 
>> Again, thank you so much! I really appreciate your help in
>> troubleshooting this.
> 
> My interpretation is that the BIOS by default starts with PCI PM 
> enabled.  When you test without 4d4c10f763 and 907a7a2e5b it will stay 
> enabled.  But when those commits are present it gets disabled when going 
> to D0 and that causes device to drop off the bus.
> 
> How about with pcie_port_pm=off instead of pcie_aspm=off?  Do things work?
> 
> My current thought is that the change (setting to D0 explicitly at boot- 
> up) exposed a bug in the platform.  But the fact that it works without 
> ASPM is confusing to me.
> 
> Bjorn - any thoughts here?

By happenstance I came across this earlier.

https://lore.kernel.org/linux-pm/aPJ4pZFENCTx9yhy@google.com/T/#m55aceae9153a1aa195635fe48aadb0888c795e49

Does that help by chance?

> 
>>
>> PS: I'm trimming the email quotes as per
>> https://subspace.kernel.org/etiquette.html#trim-your-quotes-when- 
>> replying.
>> I've never done this before and it feels wrong, but it is indeed easier
>> to follow the conversation if I do this.
> 
>