Re: [PATCH v3 7/8] wifi: wfx: allow to send frames during ROC

[Sverdlin, Alexander]

Hi Jerome,

On Tue, 2024-11-26 at 15:45 +0100, Jérôme Pouiller wrote:
> In wfx_add_interface(), the list of wvif is protected by conf_lock.
> However, wfx_tx_queues_get_skb() is not protected by conf_lock. We
> initialize struct wvif before to add it to the wvif list and we
> consider it is sufficient. However, after reading memory-barriers.txt
> again, it's probably a wrong assumption.
> 
> 
> So, maybe this could fix the issue:
> 
> diff --git i/drivers/net/wireless/silabs/wfx/sta.c w/drivers/net/wireless/silabs/wfx/sta.c
> index a904602f02ce..b22ea4243c0f 100644
> --- i/drivers/net/wireless/silabs/wfx/sta.c
> +++ w/drivers/net/wireless/silabs/wfx/sta.c
> @@ -748,6 +748,7 @@ int wfx_add_interface(struct ieee80211_hw *hw, struct ieee80211_vif *vif)
> 
>         for (i = 0; i < ARRAY_SIZE(wdev->vif); i++) {
>                 if (!wdev->vif[i]) {
> +                       smp_mb();
>                         wdev->vif[i] = vif;
>                         wvif->id = i;
>                         break;
> 
> 
> However, I am not confident in playing with memory barriers.

yes, I'd consider the whole TX path very racy again VIF add/remove.
But this is a separate topic...

-- 
Alexander Sverdlin
Siemens AG
www.siemens.com