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References: <20220117115440.60296-1-miquel.raynal@bootlin.com> <20220117115440.60296-27-miquel.raynal@bootlin.com>
In-Reply-To: <20220117115440.60296-27-miquel.raynal@bootlin.com>
From:   Alexander Aring <alex.aring@gmail.com>
Date:   Mon, 17 Jan 2022 18:14:17 -0500
Message-ID: <CAB_54W4EPDiEBHOFka99P5XF2O5gNxFhcWgjMgwaK58AcYr+Xw@mail.gmail.com>
Subject: Re: [PATCH v3 26/41] net: mac802154: Add a warning in the hot path
To:     Miquel Raynal <miquel.raynal@bootlin.com>
Cc:     Stefan Schmidt <stefan@datenfreihafen.org>,
        linux-wpan - ML <linux-wpan@vger.kernel.org>,
        "open list:NETWORKING [GENERAL]" <netdev@vger.kernel.org>,
        "linux-wireless@vger.kernel.org Wireless" 
        <linux-wireless@vger.kernel.org>,
        David Girault <david.girault@qorvo.com>,
        Romuald Despres <romuald.despres@qorvo.com>,
        Frederic Blain <frederic.blain@qorvo.com>,
        Nicolas Schodet <nico@ni.fr.eu.org>,
        Michael Hennerich <michael.hennerich@analog.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Varka Bhadram <varkabhadram@gmail.com>,
        Xue Liu <liuxuenetmail@gmail.com>, Alan Ott <alan@signal11.us>,
        Thomas Petazzoni <thomas.petazzoni@bootlin.com>
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Hi,

On Mon, 17 Jan 2022 at 06:55, Miquel Raynal <miquel.raynal@bootlin.com> wrote:
>
> We should never start a transmission after the queue has been stopped.
>
> But because it might work we don't kill the function here but rather
> warn loudly the user that something is wrong.
>
> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> ---
>  net/mac802154/tx.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/net/mac802154/tx.c b/net/mac802154/tx.c
> index 18ee6fcfcd7f..de5ecda80472 100644
> --- a/net/mac802154/tx.c
> +++ b/net/mac802154/tx.c
> @@ -112,6 +112,8 @@ ieee802154_tx(struct ieee802154_local *local, struct sk_buff *skb)
>  static netdev_tx_t
>  ieee802154_hot_tx(struct ieee802154_local *local, struct sk_buff *skb)
>  {
> +       WARN_ON(mac802154_queue_is_stopped(local));
> +

we should do a WARN_ON_ONCE() in this hot function.

- Alex