Hi Chris,
Sorry for the late reply.
> [ 17.384143] ======================================================
> [ 17.384144] WARNING: possible circular locking dependency detected
> [ 17.384146] 5.14.0-0.rc3.29.fc35.x86_64+debug #1 Not tainted
> [ 17.384147] ------------------------------------------------------
> [ 17.384148] kworker/u16:8/554 is trying to acquire lock:
> [ 17.384149] ffff91e2af7d80e8 (&sta->rate_ctrl_lock){+.-.}-{2:2},
> at: rate_control_get_rate+0xc0/0x140 [mac80211]
> [ 17.384197]
> but task is already holding lock:
> [ 17.384198] ffff91e2af7d8130 (&sta->lock){+.-.}-{2:2}, at:
> ieee80211_stop_tx_ba_cb+0x2e/0x1e0 [mac80211]
> [ 17.384229]
>
> dmesg:
> https://drive.google.com/file/d/1A5aZNMf_qXFU6arthGyu_FEIYV08V7wv/view?usp=sharing
I can confirm this is a problem, basically we have
aggregation start:
* take sta's rate lock
* call driver's rate control
* that decides to start aggregation
* calls ieee80211_start_tx_ba_session()
* takes sta lock
aggregation stop:
* ieee80211_stop_tx_ba_cb() is called
* takes sta lock
* releases TXQ from aggregation-related stop by
calling ieee80211_agg_start_txq()
* calls schedule_and_wake_txq()
* calls driver
* driver retrieves from, which calls rate control
* takes sta's rate lock
If you could, I'd appreciate if you filed a bug report on bugzilla.kernel.org (see also
https://wireless.wiki.kernel.org/en/users/drivers/iwlwifi/debugging#how_to_report
for the product/component)
It's not obvious to me immediately how to fix it, so I'd prefer to track
it as a bug report.
johannes
