lkml.org 
[lkml]   [2019]   [Jul]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH net] mvpp2: refactor MTU change code
Hi Matteo,

On Fri, Jul 26, 2019 at 01:19:31AM +0200, Matteo Croce wrote:
> The MTU change code can call napi_disable() with the device already down,
> leading to a deadlock. Also, lot of code is duplicated unnecessarily.
>
> Rework mvpp2_change_mtu() to avoid the deadlock and remove duplicated code.
>
> Signed-off-by: Matteo Croce <mcroce@redhat.com>

As this is a fix sent to net, you could add a Fixes: tag.

Otherwise this looks good,
Acked-by: Antoine Tenart <antoine.tenart@bootlin.com>

Thanks!
Antoine

> ---
> .../net/ethernet/marvell/mvpp2/mvpp2_main.c | 41 ++++++-------------
> 1 file changed, 13 insertions(+), 28 deletions(-)
>
> diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> index 2f7286bd203b..60eb98f99571 100644
> --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> @@ -3612,6 +3612,7 @@ static int mvpp2_set_mac_address(struct net_device *dev, void *p)
> static int mvpp2_change_mtu(struct net_device *dev, int mtu)
> {
> struct mvpp2_port *port = netdev_priv(dev);
> + bool running = netif_running(dev);
> int err;
>
> if (!IS_ALIGNED(MVPP2_RX_PKT_SIZE(mtu), 8)) {
> @@ -3620,40 +3621,24 @@ static int mvpp2_change_mtu(struct net_device *dev, int mtu)
> mtu = ALIGN(MVPP2_RX_PKT_SIZE(mtu), 8);
> }
>
> - if (!netif_running(dev)) {
> - err = mvpp2_bm_update_mtu(dev, mtu);
> - if (!err) {
> - port->pkt_size = MVPP2_RX_PKT_SIZE(mtu);
> - return 0;
> - }
> -
> - /* Reconfigure BM to the original MTU */
> - err = mvpp2_bm_update_mtu(dev, dev->mtu);
> - if (err)
> - goto log_error;
> - }
> -
> - mvpp2_stop_dev(port);
> + if (running)
> + mvpp2_stop_dev(port);
>
> err = mvpp2_bm_update_mtu(dev, mtu);
> - if (!err) {
> + if (err) {
> + netdev_err(dev, "failed to change MTU\n");
> + /* Reconfigure BM to the original MTU */
> + mvpp2_bm_update_mtu(dev, dev->mtu);
> + } else {
> port->pkt_size = MVPP2_RX_PKT_SIZE(mtu);
> - goto out_start;
> }
>
> - /* Reconfigure BM to the original MTU */
> - err = mvpp2_bm_update_mtu(dev, dev->mtu);
> - if (err)
> - goto log_error;
> -
> -out_start:
> - mvpp2_start_dev(port);
> - mvpp2_egress_enable(port);
> - mvpp2_ingress_enable(port);
> + if (running) {
> + mvpp2_start_dev(port);
> + mvpp2_egress_enable(port);
> + mvpp2_ingress_enable(port);
> + }
>
> - return 0;
> -log_error:
> - netdev_err(dev, "failed to change MTU\n");
> return err;
> }
>
> --
> 2.21.0
>

--
Antoine Ténart, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

\
 
 \ /
  Last update: 2019-07-26 14:51    [W:0.048 / U:5.540 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site