Received-SPF: pass (google.com: domain of linux-wireless-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Kalle Valo <kvalo@kernel.org>
To:     Alexander Wetzel <alexander@wetzel-home.de>
Cc:     linux-wireless@vger.kernel.org,
        Johannes Berg <johannes@sipsolutions.net>,
        Felix Fietkau <nbd@nbd.name>, stable@vger.kernel.org
Subject: Re: [PATCH] mac80211: Ensure vif queues are operational after start
References: <20220915130946.302803-1-alexander@wetzel-home.de>
Date:   Fri, 16 Sep 2022 08:38:31 +0300
In-Reply-To: <20220915130946.302803-1-alexander@wetzel-home.de> (Alexander
        Wetzel's message of "Thu, 15 Sep 2022 15:09:46 +0200")
Message-ID: <87y1ujanfs.fsf@kernel.org>
User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux)
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

Alexander Wetzel <alexander@wetzel-home.de> writes:

> Make sure local->queue_stop_reasons and vif.txqs_stopped stay in sync.
>
> When a new vif is created the queues may end up in an inconsistent state
> and be inoperable:
> Communication not using iTXQ will work, allowing to e.g. complete the
> association. But the 4-way handshake will time out. The sta will not
> send out any skbs queued in iTXQs.
>
> All normal attempts to start the queues will fail when reaching this
> state.
> local->queue_stop_reasons will have marked all queues as operational but
> vif.txqs_stopped will still be set, creating an inconsistent internal
> state.
>
> In reality this seems to be race between the mac80211 function
> ieee80211_do_open() setting SDATA_STATE_RUNNING and the wake_txqs_tasklet:
> Depending on the driver and the timing the queues may end up to be
> operational or not.
>
> Cc: stable@vger.kernel.org
> Fixes: f856373e2f31 ("wifi: mac80211: do not wake queues on a vif that is being stopped")
> Signed-off-by: Alexander Wetzel <alexander@wetzel-home.de>
> ---
>  net/mac80211/util.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

The title is missing "wifi:", but no need to resend because of this. I
assume Johannes will fix it during commit.

-- 
https://patchwork.kernel.org/project/linux-wireless/list/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches