Re: [REGRESSION] wifi: brcmfmac: add firmware vendor info in driver info

[Kalle Valo <kvalo@kernel.org>]

Hans de Goede <hdegoede@redhat.com> writes:

> On 5/10/23 10:25, Felix wrote:
>> Changes made by the mentioned commit lead to Oops when waking up after
>> suspend to RAM.
>> 
>> When waking up a Dell XPS 13 9350 with BCM4350 wifi card after suspend
>> to RAM, the kernel hangs with a NULL pointer dereference and Oops. The
>> issues was introduced by commit
>> da6d9c8ecd00e20218461007948f2b0a8e7fa242 and only happens when the
>> brcmfmac module is loaded. This issue is the reason we could not
>> upgrade to newer kernels than the 6.1 series on the affected machine.
>> 
>> 
>> Details:
>> 
>> On a Dell XPS 13 9350 laptop with Broadcom BCM4350 wifi card (according
>> to lspci), every kernel starting with 6.2 hangs when waking up after
>> suspend to RAM. The issue persisted as of May 2nd (last tested commit
>> was 348551ddaf311c76b01cdcbaf61b6fef06a49144). Passing the debug and
>> no_console_suspend parameters to the kernel show that a NULL pointer
>> dereference and an Oops happen at wakeup. Please find the kernel
>> messages readable on the screen at this point attached
>> (kernel_log_after_suspend.txt).
>> 
>> A bisection was successful and produced the first bad commit
>> [da6d9c8ecd00e20218461007948f2b0a8e7fa242] wifi: brcmfmac: add firmware
>> vendor info in driver info
>> I've attached the bisection log as well (bisect.txt).
>> 
>> Suspend to RAM works on this machine on newer kernels once the brcmfmac
>> module is unloaded.
>> 
>> Distribution: Arch Linux
>> Architecture: x86_64
>> Device: Dell XPS 13 9350 with BCM4350 wifi card
>> Kernel config used at compilation (created using the Arch Linux default
>> config and make olddefconfig):
>> https://gist.githubusercontent.com/maclomhair/e33fa7eece8f8c77e5a88c4eede2f523/raw/429dfb022498c026225865dbb3ab2f75d5030a54/config
>> Dmesg output after boot:
>> https://gist.githubusercontent.com/maclomhair/47c75fa759d93800e7fb5e937fabef3e/raw/10750996a1ea9dcb3fa14d9b94e11fedd3abf280/dmesg
>> 
>> #regzbot introduced da6d9c8ecd00e20218461007948f2b0a8e7fa242
>
> Thank you for reporting this and thank you for bisecting it too!
>
> As a result of your excellent bug report I've been able to write
> a fix for this. I'm confident enough in the fix that I've submitted
> it upstream right away.
>
> But it would still be good if you can test the fix and let us know
> if it fixes this issue for you. You should have received a copy
> of the patch when I submitted it upstream.

For the archives here's the patch:

https://patchwork.kernel.org/project/linux-wireless/patch/20230510100050.27099-1-hdegoede@redhat.com/

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