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From:   Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= <toke@redhat.com>
To:     Johannes Berg <johannes@sipsolutions.net>,
        Jens Axboe <axboe@kernel.dk>,
        Emmanuel Grumbach <emmanuel.grumbach@intel.com>,
        Luca Coelho <luciano.coelho@intel.com>,
        "Jason A. Donenfeld" <Jason@zx2c4.com>,
        Steve French <smfrench@gmail.com>
Cc:     "linux-wireless\@vger.kernel.org" <linux-wireless@vger.kernel.org>,
        Networking <netdev@vger.kernel.org>
Subject: Re: iwlwifi warnings in 5.5-rc1
In-Reply-To: <d4a48cbdc4b0db7b07b8776a1ee70b140e8a9bbf.camel@sipsolutions.net>
References: <ceb74ea2-6a1b-4cef-8749-db21a2ee4311@kernel.dk> <d4a48cbdc4b0db7b07b8776a1ee70b140e8a9bbf.camel@sipsolutions.net>
Date:   Wed, 11 Dec 2019 15:09:58 +0100
Message-ID: <87o8wfeyx5.fsf@toke.dk>
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Johannes Berg <johannes@sipsolutions.net> writes:

> ++ others who reported this
>
> On Tue, 2019-12-10 at 13:46 -0700, Jens Axboe wrote:
>
>> ------------[ cut here ]------------
>> STA b4:75:0e:99:1f:e0 AC 2 txq pending airtime underflow: 4294967088, 20=
8
>
> We think this is due to TSO, the change below will disable the AQL again
> for now until we can figure out how to really fix it. I think I'll do
> the equivalent for 5.5 and maybe leave it enabled only for ath10k, or
> something like that ...

If we're doing this on a per-driver basis, let's make it a proper
NL80211_EXT_FEATURE and expose it to userspace; that way users can at
least discover if it's supported on their device. I can send a patch
adding that...

Maybe we should untangle this from airtime_flags completely, since if we
just use the flags people could conceivably end up disabling it by
mistake, couldn't they?

-Toke