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Date:   Wed, 21 Aug 2019 10:47:24 +0200
From:   Stanislaw Gruszka <sgruszka@redhat.com>
To:     Felix Fietkau <nbd@nbd.name>
Cc:     Lorenzo Bianconi <lorenzo.bianconi@redhat.com>,
        linux-wireless <linux-wireless@vger.kernel.org>,
        Ryder Lee <ryder.lee@mediatek.com>, Roy Luo <royluo@google.com>
Subject: Re: [PATCH 5.3] mt76: mt76x0e: don't use hw encryption for MT7630E
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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.

Stanislaw