Re: [PATCH v3 1/3] wifi: rtw88: Move register access from rtw_bf_assoc() outside the RCU

From: Kalle Valo
Date: Mon Jan 16 2023 - 11:40:03 EST


Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx> wrote:

> USB and (upcoming) SDIO support may sleep in the read/write handlers.
> Shrink the RCU critical section so it only cover the call to
> ieee80211_find_sta() and finding the ic_vht_cap/vht_cap based on the
> found station. This moves the chip's BFEE configuration outside the
> rcu_read_lock section and thus prevent "scheduling while atomic" or
> "Voluntary context switch within RCU read-side critical section!"
> warnings when accessing the registers using an SDIO card (which is
> where this issue has been spotted in the real world - but it also
> affects USB cards).
>
> Reviewed-by: Ping-Ke Shih <pkshih@xxxxxxxxxxx>
> Tested-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>

3 patches applied to wireless-next.git, thanks.

8a1e2fd8e2da wifi: rtw88: Move register access from rtw_bf_assoc() outside the RCU
313f6dc7c5ed wifi: rtw88: Use rtw_iterate_vifs() for rtw_vif_watch_dog_iter()
2931978cd74f wifi: rtw88: Use non-atomic sta iterator in rtw_ra_mask_info_update()

--
https://patchwork.kernel.org/project/linux-wireless/patch/20230108211324.442823-2-martin.blumenstingl@xxxxxxxxxxxxxx/

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