bizarre network problem on kernel 6.6.4

[Jeff Johnson]

On 12/5/2023 9:04 AM, Kalle Valo wrote:
> Fourhundred Thecat <400thecat at ik.me> writes:
> 
>> On 05/12/2023 13.11, Kalle Valo wrote:
>>> Fourhundred Thecat <400thecat at ik.me> writes:
>>>
>>>> I have the most bizarre network problem on my laptop that I have ever
>>>> seen, and I don't even know where to start:
>>>>
>>>> This is lenovo T14s Gen 4, using qualcomm driver ath11k_pci
>>>>
>>>> Previously I was using kernel 6.6.1 and wireless network was working fine.
>>>>
>>>> Now I compiled kernel 6.6.4 with identical config, and when I boot it,
>>>> wireless network does not work:
>>>
>>> Did you verify that booting back to 6.6.1 fixes the problem? That would
>>> rule out that this isn't due to some external reasons (user space or
>>> network)
>>>
>>> If you can verify that 6.6.1 always works and 6.6.4 always fails I would
>>> just try to git bisect the issue. It shouldn't take too long.
>>
>> yes. I verified multiple times that 6.6.1 works, and 6.6.4 has this problem.
>>
>> I am not really familiar with git bisect, and I am also not a kernel
>> developer.
> 
> git bisect is a very useful tool, I recommend learning it as it makes so
> much easier to find the culprit for regressions. You don't have to be a
> kernel developer, it's enough that you know how to compile and install a
> kernel.
> 
> Here's one doc I found with google, hopefully it helps:
> 
> https://wiki.gentoo.org/wiki/Kernel_git-bisect
> 
> Here's one from kernel documentation:
> 
> https://docs.kernel.org/admin-guide/bug-bisect.html
> 
>> But I tried checking out linux kernel git repository, switched to tag
>> 6.6. and looked inside drivers/net/wireless/ath/ath11k trying to spot
>> any change. But git log shows last change on 2023-08-30, whereas kernel
>> 6.6.4 was released few days ago
> 
> I assume you were looking at Torvalds' tree only. The release 6.6.4
> means that you are using a stable release which are in linux-stable
> tree, the gentoo doc above should help more.

FWIW it seems that the only changes to ath11k have been trivial:

% git log --oneline v6.6.1..v6.6.4 -- drivers/net/wireless/ath/ath11k/
e83246ecd3b1 wifi: ath11k: fix gtk offload status event locking
69cede2a5a5f wifi: ath11k: fix htt pktlog locking
21ebb0aba580 wifi: ath11k: fix dfs radar event locking
c5b914528e55 wifi: ath11k: fix temperature event locking
2d88afdac295 wifi: ath11k: fix Tx power value during active CAC
d412d0ef300f wifi: ath11k: fix boot failure with one MSI vector
% git remote -v
origin  git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
(fetch)
origin  git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
(push)

Suggest you follow the instructions at the following link and create a
kernel bug report:
https://wireless.wiki.kernel.org/en/users/drivers/ath11k/bugreport

Meanwhile I'll build and load 6.6.4 on my laptop.

/jeff