Re: [Linux 5.18-rc1] WARNING: possible circular locking dependency detected at (rtw_ops_config, ieee80211_mgd_probe_ap)

From: Johannes Berg
Date: Mon Apr 11 2022 - 10:47:11 EST


On Thu, 2022-04-07 at 08:26 +0700, Ammar Faizi wrote:
>
> [21860.955836] Possible unsafe locking scenario:
>
> [21860.955837] CPU0 CPU1
> [21860.955837] ---- ----
> [21860.955838] lock(&local->iflist_mtx);
> [21860.955839] lock(&rtwdev->mutex);
> [21860.955840] lock(&local->iflist_mtx);
> [21860.955841] lock(&rtwdev->mutex);
> [21860.955842]
> *** DEADLOCK ***
>

The driver needs to fix this, cannot call ieee80211_iterate_interfaces()
inside a section locked this way. I _think_ this deadlock used to be
documented by it looks like that documentation got moved around or
something.

johannes