* [PATCH net] mvpp2: refactor MTU change code
@ 2019-07-25 23:19 Matteo Croce
2019-07-26 12:50 ` Antoine Tenart
2019-07-27 20:24 ` David Miller
0 siblings, 2 replies; 4+ messages in thread
From: Matteo Croce @ 2019-07-25 23:19 UTC (permalink / raw)
To: netdev
Cc: Antoine Tenart, Maxime Chevallier, Marcin Wojtas, Stefan Chulski, LKML
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>
---
.../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
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH net] mvpp2: refactor MTU change code
2019-07-25 23:19 [PATCH net] mvpp2: refactor MTU change code Matteo Croce
@ 2019-07-26 12:50 ` Antoine Tenart
2019-07-26 14:26 ` Matteo Croce
2019-07-27 20:24 ` David Miller
1 sibling, 1 reply; 4+ messages in thread
From: Antoine Tenart @ 2019-07-26 12:50 UTC (permalink / raw)
To: Matteo Croce
Cc: netdev, Antoine Tenart, Maxime Chevallier, Marcin Wojtas,
Stefan Chulski, LKML
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
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH net] mvpp2: refactor MTU change code
2019-07-26 12:50 ` Antoine Tenart
@ 2019-07-26 14:26 ` Matteo Croce
0 siblings, 0 replies; 4+ messages in thread
From: Matteo Croce @ 2019-07-26 14:26 UTC (permalink / raw)
To: Antoine Tenart
Cc: netdev, Maxime Chevallier, Marcin Wojtas, Stefan Chulski, LKML
On Fri, Jul 26, 2019 at 2:50 PM Antoine Tenart
<antoine.tenart@bootlin.com> wrote:
>
> 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
It seems to me that the fixes tag should refer to the driver inclusion:
Fixes: 3f518509dedc ("ethernet: Add new driver for Marvell Armada 375
network unit")
--
Matteo Croce
per aspera ad upstream
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH net] mvpp2: refactor MTU change code
2019-07-25 23:19 [PATCH net] mvpp2: refactor MTU change code Matteo Croce
2019-07-26 12:50 ` Antoine Tenart
@ 2019-07-27 20:24 ` David Miller
1 sibling, 0 replies; 4+ messages in thread
From: David Miller @ 2019-07-27 20:24 UTC (permalink / raw)
To: mcroce
Cc: netdev, antoine.tenart, maxime.chevallier, mw, stefanc, linux-kernel
From: Matteo Croce <mcroce@redhat.com>
Date: Fri, 26 Jul 2019 01:19:31 +0200
> 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>
Please resubmit with the Fixes: tag.
Please do not line break the Fixes: tag no matter how many characters
it ends up being in total.
Thanks.
^ permalink raw reply [flat|nested] 4+ messages in thread
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2019-07-26 12:50 ` Antoine Tenart
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2019-07-27 20:24 ` David Miller
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