On 3/1/19 5:48 AM, Felix Fietkau wrote:

There are several scenarios in which mac80211 can call drv_wake_tx_queue after ieee80211_restart_hw has been called and has not yet completed. Driver private structs are considered uninitialized until mac80211 has uploaded the vifs, stations and keys again, so using private tx queue data during that time is not safe.

The driver can also not rely on drv_reconfig_complete to figure out when it is safe to accept drv_wake_tx_queue calls again, because it is only called after all tx queues are woken again.

To fix this, bail out early in drv_wake_tx_queue if local->in_reconfig is set.

This reminded me of a patch I posted back in 2016. The discussion just sort of ended on it, but curious if you have a new opinion on it after debugging the issue in this patch:

https://patchwork.kernel.org/patch/9457709/

For what its worth, I've been using the patch above since I posted it, and it seems to work well for ath9k and ath10k.

Thanks, Ben

Cc: stable@vger.kernel.org Signed-off-by: Felix Fietkau nbd@nbd.name

---

net/mac80211/driver-ops.h | 3 +++ 1 file changed, 3 insertions(+)

diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h index 28d022a3eee3..ae4f0be3b393 100644 --- a/net/mac80211/driver-ops.h +++ b/net/mac80211/driver-ops.h @@ -1195,6 +1195,9 @@ static inline void drv_wake_tx_queue(struct ieee80211_local *local, { struct ieee80211_sub_if_data *sdata = vif_to_sdata(txq->txq.vif);

• if (local->in_reconfig)

• return;
  

• if (!check_sdata_in_driver(sdata)) return;