Re: Bug 215715 - PCI device (iwlwifi) is not working due to PCI power state change issues #forregzbot

[Thorsten Leemhuis <regressions@leemhuis.info>]

On 10.04.22 11:11, Thorsten Leemhuis wrote:
> TWIMC: this mail is primarily send for documentation purposes and for
> regzbot, my Linux kernel regression tracking bot. These mails usually
> contain '#forregzbot' in the subject, to make them easy to spot and filter.
> 
> #regzbot monitor: https://lore.kernel.org/all/11980172.O9o76ZdvQC@kreacher/

#regzbot fixed-by: 92597f97a40bf661

> On 29.03.22 10:49, Thorsten Leemhuis wrote:
>> On 28.03.22 15:33, Thorsten Leemhuis wrote:
>>> Hi, this is your Linux kernel regression tracker.
>>>
>>> Rafael, I noticed a regression report in bugzilla.kernel.org that afaics
>>> nobody acted upon since it was reported about a week ago, that's why I
>>> decided to forward it to the lists, maintainers, and the author of the
>>> culprit. To quote from
>>> https://bugzilla.kernel.org/show_bug.cgi?id=215715 :
>>>
>>>>  Stefan Gottwald 2022-03-21 13:31:43 UTC
>>>>
>>>> Created attachment 300589 [details]
>>>> dmesg output from error case
>>>>
>>>> We got a Elo AIO i2 device which most current BIOS where WiFi was working with Kernel 5.12.x but stopped working since Kernel 5.13.19 and newer (5.17.0-rc5).
>>>>
>>>> The kernel error message is:
>>>>
>>>> [    3.419766] iwlwifi 0000:01:00.0: can't change power state from D3cold to D0 (config space inaccessible)
>>>> [    3.419781] iwlwifi 0000:01:00.0: can't change power state from D3cold to D0 (config space inaccessible)
>>>> [    3.419975] iwlwifi 0000:01:00.0: HW_REV=0xFFFFFFFF, PCI issues?
>>>> [    3.420911] iwlwifi: probe of 0000:01:00.0 failed with error -5
>>>>
>>>> The issue can be solved by adding the iwlwifi driver to the initramfs so it is loaded much earlier and seems to work.
>>>>
>>>> To narrow down the issue I did an git bisect between v5.13.18 and v5.13.19 mainline kernel version which got me to following commit which if reverted fix the issue on this device.
>>>>
>>>> Reverting commit d0660d8ab123ea471064f0828f290bec9593e16b : PCI: Use pci_update_current_state() in pci_enable_device_flags()
>>>
>>> FWIW, that afaics is d0660d8ab123 ("PCI: Use pci_update_current_state()
>>> in pci_enable_device_flags()") in mainline.
>>
>> Sorry, I made a (obvious) cut-n-paste error there: the stable commit
>> mentioned by the reporter is 14858dcc3b35 ("PCI: Use
>> pci_update_current_state() in pci_enable_device_flags()") in mainline.
>>
>> #regzbot introduced: 14858dcc3b35
>>
>>>> resolve the issue also in the newer kernels. Seems like the function platform_pci_get_power_state is always returning PCI_D3cold on this device also if this is not true.
>>>
>>> Could somebody take a look into this? Or was this discussed somewhere
>>> else already? Or even fixed?
>>>
>>> Anyway, to get this tracked:
>>>
>>> #regzbot introduced: d0660d8ab123ea471064f0828f290bec9593e16b
>>> #regzbot from: Stefan Gottwald <gottwald@igel.com>
>>> #regzbot title: pci/iwlwifi: wifi is not working due to PCI power state
>>> change issues
>>> #regzbot link: https://bugzilla.kernel.org/show_bug.cgi?id=215715
>>>
>>> Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)
>>>
>>> P.S.: As the Linux kernel's regression tracker I'm getting a lot of
>>> reports on my table. I can only look briefly into most of them and lack
>>> knowledge about most of the areas they concern. I thus unfortunately
>>> will sometimes get things wrong or miss something important. I hope
>>> that's not the case here; if you think it is, don't hesitate to tell me
>>> in a public reply, it's in everyone's interest to set the public record
>>> straight.
>>>