From: Florian Fainelli <f.fainelli@gmail.com>
To: "Niklas Söderlund" <niklas.soderlund+renesas@ragnatech.se>,
"Sergei Shtylyov" <sergei.shtylyov@cogentembedded.com>,
"David S . Miller" <davem@davemloft.net>,
netdev@vger.kernel.org
Cc: linux-renesas-soc@vger.kernel.org
Subject: Re: [PATCH v2] ravb: add support for changing MTU
Date: Fri, 16 Feb 2018 11:42:09 -0800 [thread overview]
Message-ID: <aa1378e7-3d2f-fec0-7000-f7f62ddd6100@gmail.com> (raw)
In-Reply-To: <20180216161008.12882-1-niklas.soderlund+renesas@ragnatech.se>
On 02/16/2018 08:10 AM, Niklas Söderlund wrote:
> Allow for changing the MTU within the limit of the maximum size of a
> descriptor (2048 bytes). Add the callback to change MTU from user-space
> and take the configurable MTU into account when configuring the
> hardware.
>
> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> ---
>
> +static int ravb_change_mtu(struct net_device *ndev, int new_mtu)
> +{
> + if (netif_running(ndev))
> + return -EBUSY;
> +
> + ndev->mtu = new_mtu;
> + netdev_update_features(ndev);
Don't you somehow need to quiesce the RX DMA and make sure you that you
re-allocate all RX buffers within priv->rx_skb[q][entry] such that they
will be able to accept a larger buffer size?
If we put the ravb interface under high RX load and we change the MTU on
the fly, can we crash the kernel?
--
Florian
next prev parent reply other threads:[~2018-02-16 19:42 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-16 16:10 [PATCH v2] ravb: add support for changing MTU Niklas Söderlund
2018-02-16 19:42 ` Florian Fainelli [this message]
2018-02-16 19:43 ` Sergei Shtylyov
2018-02-16 19:45 ` Florian Fainelli
2018-02-16 21:35 ` David Miller
2018-02-17 9:08 ` Sergei Shtylyov
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