On 2019-08-21 10:47, Stanislaw Gruszka wrote: > On Tue, Aug 20, 2019 at 01:24:39PM +0200, Stanislaw Gruszka wrote: >> > Can you test if disabling hw encryption only for shared or only for >> > pairwise keys makes any difference? >> >> Disabling only pairwise keys helps. Disabling only shared keys does >> not help. >> >> Not sure if this will be helpful information or make things more >> confusing, but seems the difference between mt76_txq_schedule() >> and tasklet_schedule() in mt76_wake_tx_queue() is that on >> mt76_txq_schedule() some tx packets are serialized by dev->rx_lock >> (because some ARP and TCP packets are sent via network stack as response >> of incoming packet within ieee80211_rx_napi() call). Removing >> spin_lock(&dev->rx_lock) in mt76_rx_complete() make the problem >> reproducible again with mt76_txq_schedule() & HW encryption. > > So, I think this is FW/HW issue related with encryption and ordering > and we should apply patch originally posted in this thread that > disable HW encryption for MT7630E. > > I do not think we should disable HW encryption only for pairwise keys, > because FW/HW can have the same bug for shared keys, but is not > triggered in my test, as we do not sent lot of group frames. I'm still not convinced that this is just the hardware implementation of hw crypto being faulty. I think it's more likely that there's a bug in the tx path somewhere, which causes hangs on MT7630E but remains hidden (or at least recoverable) on other devices. I'm currently reviewing key handling in the mac80211 fast-xmit codepath and get the feeling that something might be racy there. I will let you know when I make some progress with that review. If we can't find the bug soon, then I'm fine with merging this patch. Right now, I would like to see first if we can fix it properly. - Felix
