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? - Felix
