RE: PROBLEM: kernel warns about voluntary context switch within RCU critical section in rtw88_usb

RE: PROBLEM: kernel warns about voluntary context switch within RCU critical section in rtw88_usb

[Ping-Ke Shih]

From: Sergey Korolev <korolev.sergey@gmail.com> 
Sent: Monday, August 21, 2023 10:28 PM
To: Ping-Ke Shih <pkshih@realtek.com>; Kalle Valo <kvalo@kernel.org>; linux-wireless@vger.kernel.org; linux-kernel@vger.kernel.org
Subject: PROBLEM: kernel warns about voluntary context switch within RCU critical section in rtw88_usb
> 
> Please note I use an unmodified driver from the upstream 28c11c29494f1b34e39641eead9c60a8bd26170d
> ("wifi: rtw88: fix not entering PS mode after AP stops") build for 6.2 kernel (Ubuntu 23.04).

I feel Martin has been addressed this problem during development of SDIO and USB
by 8a1e2fd8e2da ("wifi: rtw88: Move register access from rtw_bf_assoc() outside the RCU")
Please take a look if this patch is existing in your source. 

Ping-Ke

Re: PROBLEM: kernel warns about voluntary context switch within RCU critical section in rtw88_usb

[Kalle Valo]

Ping-Ke Shih <pkshih@realtek.com> writes:

> From: Sergey Korolev <korolev.sergey@gmail.com> 
> Sent: Monday, August 21, 2023 10:28 PM
> To: Ping-Ke Shih <pkshih@realtek.com>; Kalle Valo <kvalo@kernel.org>; linux-wireless@vger.kernel.org; linux-kernel@vger.kernel.org
> Subject: PROBLEM: kernel warns about voluntary context switch within RCU critical section in rtw88_usb
>> 
>> Please note I use an unmodified driver from the upstream 28c11c29494f1b34e39641eead9c60a8bd26170d
>> ("wifi: rtw88: fix not entering PS mode after AP stops") build for 6.2 kernel (Ubuntu 23.04).
>
> I feel Martin has been addressed this problem during development of SDIO and USB
> by 8a1e2fd8e2da ("wifi: rtw88: Move register access from rtw_bf_assoc() outside the RCU")
> Please take a look if this patch is existing in your source. 

Commit 8a1e2fd8e2da was merged to v6.3-rc1 so v6.2 won't have it.

-- 
https://patchwork.kernel.org/project/linux-wireless/list/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

RE: PROBLEM: kernel warns about voluntary context switch within RCU critical section in rtw88_usb

[Ping-Ke Shih]

> -----Original Message-----
> From: Kalle Valo <kvalo@kernel.org>
> Sent: Tuesday, August 22, 2023 1:42 PM
> To: Ping-Ke Shih <pkshih@realtek.com>
> Cc: Sergey Korolev <korolev.sergey@gmail.com>; linux-wireless@vger.kernel.org;
> linux-kernel@vger.kernel.org
> Subject: Re: PROBLEM: kernel warns about voluntary context switch within RCU critical section in rtw88_usb
> 
> Ping-Ke Shih <pkshih@realtek.com> writes:
> 
> > From: Sergey Korolev <korolev.sergey@gmail.com>
> > Sent: Monday, August 21, 2023 10:28 PM
> > To: Ping-Ke Shih <pkshih@realtek.com>; Kalle Valo <kvalo@kernel.org>; linux-wireless@vger.kernel.org;
> linux-kernel@vger.kernel.org
> > Subject: PROBLEM: kernel warns about voluntary context switch within RCU critical section in rtw88_usb
> >>
> >> Please note I use an unmodified driver from the upstream 28c11c29494f1b34e39641eead9c60a8bd26170d
> >> ("wifi: rtw88: fix not entering PS mode after AP stops") build for 6.2 kernel (Ubuntu 23.04).
> >
> > I feel Martin has been addressed this problem during development of SDIO and USB
> > by 8a1e2fd8e2da ("wifi: rtw88: Move register access from rtw_bf_assoc() outside the RCU")
> > Please take a look if this patch is existing in your source.
> 
> Commit 8a1e2fd8e2da was merged to v6.3-rc1 so v6.2 won't have it.
> 

Sergey said he uses driver from 28c11c29494f that is v6.4-rc5 or v6.5, so
seemingly it should include Martin's patch. Not sure what is wrong.

Ping-Ke