On Wed, Aug 21, 2019 at 12:40:14PM +0200, Felix Fietkau wrote: > On 2019-08-21 11:03, Felix Fietkau wrote: > > 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. > Another question: Does a watchdog restart happen before tx fails? No, we do not run wdt_work for mt76x0e. Stanislaw
