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Message-ID: <3420d73e667b01ec64bf0cc9da6232b41e862860.camel@sipsolutions.net>
Subject: Re: iwlwifi warnings in 5.5-rc1
From:   Johannes Berg <johannes@sipsolutions.net>
To:     Toke =?ISO-8859-1?Q?H=F8iland-J=F8rgensen?= <toke@redhat.com>,
        Jens Axboe <axboe@kernel.dk>,
        Emmanuel Grumbach <emmanuel.grumbach@intel.com>,
        Luca Coelho <luciano.coelho@intel.com>
Cc:     "linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>,
        Networking <netdev@vger.kernel.org>
Date:   Wed, 11 Dec 2019 11:11:04 +0100
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         <9727368004ceef03f72d259b0779c2cf401432e1.camel@sipsolutions.net>
         <878snjgs5l.fsf@toke.dk>
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On Wed, 2019-12-11 at 09:53 +0100, Toke Høiland-Jørgensen wrote:
> Johannes Berg <johannes@sipsolutions.net> writes:
> 
> > On Tue, 2019-12-10 at 13:46 -0700, Jens Axboe wrote:
> > > Hi,
> > > 
> > > Since the GRO issue got fixed, iwlwifi has worked fine for me.
> > > However, on every boot, I get some warnings:
> > > 
> > > ------------[ cut here ]------------
> > > STA b4:75:0e:99:1f:e0 AC 2 txq pending airtime underflow: 4294967088, 208
> > 
> > Yeah, we've seen a few reports of this.
> 
> FWIW I've tried reproducing but I don't get the error with the 8265 /
> 8275 chip in my laptop. I've thought about sending a patch for mac80211
> to just clear the tx_time_est field after calling
> ieee80211_sta_update_pending_airtime() - that should prevent any errors
> from double-reporting of skbs (which is what I'm guessing is going on
> here).

It does feel like it, but I'm not sure how that'd be possible?

OK, I talked with Emmanuel and I think it's the GSO path - it'll end up
with skb_clone() and then report both of them back.

Regardless, I think I'll probably have to disable AQL and make it more
opt-in for the driver - I found a bunch of other issues ...

johannes