* [PATCH 1/1 v2 net] net: fec: fix kernel oops when plug/unplug cable many times
@ 2013-04-28 3:08 Frank Li
2013-04-29 13:47 ` Lucas Stach
2013-04-30 19:35 ` David Miller
0 siblings, 2 replies; 4+ messages in thread
From: Frank Li @ 2013-04-28 3:08 UTC (permalink / raw)
To: romieu, r.schwebel, davem, l.stach, netdev, festevam, shawn.guo, lznuaa
Cc: Frank Li
reproduce steps
1. flood ping from other machine
ping -f -s 41000 IP
2. run below script
while [ 1 ]; do ethtool -s eth0 autoneg off;
sleep 3;ethtool -s eth0 autoneg on; sleep 4; done;
You can see oops in one hour.
The reason is fec_restart clear BD but NAPI may use it.
The solution is disable NAPI and stop xmit when reset BD.
disable NAPI may sleep, so fec_restart can't be call in
atomic context.
Signed-off-by: Frank Li <Frank.Li@freescale.com>
---
Change from V1 to V2
Add netif_tx_lock(ndev) to avoid xmit runing when reset hardware
drivers/net/ethernet/freescale/fec.c | 41 +++++++++++++++++++++++++++++-----
drivers/net/ethernet/freescale/fec.h | 3 +-
2 files changed, 37 insertions(+), 7 deletions(-)
diff --git a/drivers/net/ethernet/freescale/fec.c b/drivers/net/ethernet/freescale/fec.c
index 73195f6..d140b50 100644
--- a/drivers/net/ethernet/freescale/fec.c
+++ b/drivers/net/ethernet/freescale/fec.c
@@ -403,6 +403,12 @@ fec_restart(struct net_device *ndev, int duplex)
const struct platform_device_id *id_entry =
platform_get_device_id(fep->pdev);
int i;
+ if (netif_running(ndev)) {
+ napi_disable(&fep->napi);
+ netif_stop_queue(ndev);
+ netif_tx_lock(ndev);
+ }
+
u32 temp_mac[2];
u32 rcntl = OPT_FRAME_SIZE | 0x04;
u32 ecntl = 0x2; /* ETHEREN */
@@ -559,6 +565,12 @@ fec_restart(struct net_device *ndev, int duplex)
/* Enable interrupts we wish to service */
writel(FEC_DEFAULT_IMASK, fep->hwp + FEC_IMASK);
+
+ if (netif_running(ndev)) {
+ napi_enable(&fep->napi);
+ netif_wake_queue(ndev);
+ netif_tx_unlock(ndev);
+ }
}
static void
@@ -598,8 +610,20 @@ fec_timeout(struct net_device *ndev)
ndev->stats.tx_errors++;
- fec_restart(ndev, fep->full_duplex);
- netif_wake_queue(ndev);
+ fep->timeout = 1;
+ schedule_delayed_work(&fep->delay_work, msecs_to_jiffies(1));
+}
+
+static void fec_enet_work(struct work_struct *work)
+{
+ struct fec_enet_private *fep =
+ container_of(work, struct fec_enet_private, delay_work.work);
+
+ if (fep->timeout) {
+ fep->timeout = 0;
+ fec_restart(fep->netdev, fep->full_duplex);
+ netif_wake_queue(fep->netdev);
+ }
}
static void
@@ -996,9 +1020,6 @@ static void fec_enet_adjust_link(struct net_device *ndev)
status_change = 1;
}
- /* if any of the above changed restart the FEC */
- if (status_change)
- fec_restart(ndev, phy_dev->duplex);
} else {
if (fep->link) {
fec_stop(ndev);
@@ -1010,8 +1031,14 @@ static void fec_enet_adjust_link(struct net_device *ndev)
spin_unlock:
spin_unlock_irqrestore(&fep->hw_lock, flags);
- if (status_change)
+ if (status_change) {
+ /* if any of the above changed restart the FEC,
+ * fec_restart may sleep. can't call it in spin_lock
+ */
+ if (phy_dev->link)
+ fec_restart(ndev, phy_dev->duplex);
phy_print_status(phy_dev);
+ }
}
static int fec_enet_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
@@ -1882,6 +1909,7 @@ fec_probe(struct platform_device *pdev)
if (ret)
goto failed_register;
+ INIT_DELAYED_WORK(&fep->delay_work, fec_enet_work);
return 0;
failed_register:
@@ -1918,6 +1946,7 @@ fec_drv_remove(struct platform_device *pdev)
struct resource *r;
int i;
+ cancel_delayed_work_sync(&fep->delay_work);
unregister_netdev(ndev);
fec_enet_mii_remove(fep);
del_timer_sync(&fep->time_keep);
diff --git a/drivers/net/ethernet/freescale/fec.h b/drivers/net/ethernet/freescale/fec.h
index eb43729..a367b21 100644
--- a/drivers/net/ethernet/freescale/fec.h
+++ b/drivers/net/ethernet/freescale/fec.h
@@ -260,7 +260,8 @@ struct fec_enet_private {
int hwts_rx_en;
int hwts_tx_en;
struct timer_list time_keep;
-
+ struct delayed_work delay_work;
+ int timeout;
};
void fec_ptp_init(struct net_device *ndev, struct platform_device *pdev);
--
1.7.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH 1/1 v2 net] net: fec: fix kernel oops when plug/unplug cable many times
2013-04-28 3:08 [PATCH 1/1 v2 net] net: fec: fix kernel oops when plug/unplug cable many times Frank Li
@ 2013-04-29 13:47 ` Lucas Stach
2013-05-02 2:08 ` Frank Li
2013-04-30 19:35 ` David Miller
1 sibling, 1 reply; 4+ messages in thread
From: Lucas Stach @ 2013-04-29 13:47 UTC (permalink / raw)
To: Frank Li; +Cc: romieu, r.schwebel, davem, netdev, festevam, shawn.guo, lznuaa
Hi Frank,
Am Sonntag, den 28.04.2013, 11:08 +0800 schrieb Frank Li:
> reproduce steps
> 1. flood ping from other machine
> ping -f -s 41000 IP
> 2. run below script
> while [ 1 ]; do ethtool -s eth0 autoneg off;
> sleep 3;ethtool -s eth0 autoneg on; sleep 4; done;
>
> You can see oops in one hour.
>
> The reason is fec_restart clear BD but NAPI may use it.
> The solution is disable NAPI and stop xmit when reset BD.
> disable NAPI may sleep, so fec_restart can't be call in
> atomic context.
>
> Signed-off-by: Frank Li <Frank.Li@freescale.com>
> ---
>
> Change from V1 to V2
> Add netif_tx_lock(ndev) to avoid xmit runing when reset hardware
>
> drivers/net/ethernet/freescale/fec.c | 41 +++++++++++++++++++++++++++++-----
> drivers/net/ethernet/freescale/fec.h | 3 +-
> 2 files changed, 37 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/net/ethernet/freescale/fec.c b/drivers/net/ethernet/freescale/fec.c
> index 73195f6..d140b50 100644
> --- a/drivers/net/ethernet/freescale/fec.c
> +++ b/drivers/net/ethernet/freescale/fec.c
> @@ -403,6 +403,12 @@ fec_restart(struct net_device *ndev, int duplex)
> const struct platform_device_id *id_entry =
> platform_get_device_id(fep->pdev);
> int i;
> + if (netif_running(ndev)) {
> + napi_disable(&fep->napi);
> + netif_stop_queue(ndev);
> + netif_tx_lock(ndev);
> + }
> +
> u32 temp_mac[2];
> u32 rcntl = OPT_FRAME_SIZE | 0x04;
> u32 ecntl = 0x2; /* ETHEREN */
> @@ -559,6 +565,12 @@ fec_restart(struct net_device *ndev, int duplex)
>
> /* Enable interrupts we wish to service */
> writel(FEC_DEFAULT_IMASK, fep->hwp + FEC_IMASK);
> +
> + if (netif_running(ndev)) {
> + napi_enable(&fep->napi);
> + netif_wake_queue(ndev);
> + netif_tx_unlock(ndev);
> + }
> }
>
> static void
> @@ -598,8 +610,20 @@ fec_timeout(struct net_device *ndev)
>
> ndev->stats.tx_errors++;
>
> - fec_restart(ndev, fep->full_duplex);
> - netif_wake_queue(ndev);
> + fep->timeout = 1;
> + schedule_delayed_work(&fep->delay_work, msecs_to_jiffies(1));
> +}
Why are you using delayed work here? I don't see a reason why we would
like to defer execution here. Just use schedule_work().
> +
> +static void fec_enet_work(struct work_struct *work)
> +{
> + struct fec_enet_private *fep =
> + container_of(work, struct fec_enet_private, delay_work.work);
> +
> + if (fep->timeout) {
> + fep->timeout = 0;
> + fec_restart(fep->netdev, fep->full_duplex);
> + netif_wake_queue(fep->netdev);
> + }
> }
>
> static void
> @@ -996,9 +1020,6 @@ static void fec_enet_adjust_link(struct net_device *ndev)
> status_change = 1;
> }
>
> - /* if any of the above changed restart the FEC */
> - if (status_change)
> - fec_restart(ndev, phy_dev->duplex);
> } else {
> if (fep->link) {
> fec_stop(ndev);
> @@ -1010,8 +1031,14 @@ static void fec_enet_adjust_link(struct net_device *ndev)
> spin_unlock:
> spin_unlock_irqrestore(&fep->hw_lock, flags);
>
> - if (status_change)
> + if (status_change) {
> + /* if any of the above changed restart the FEC,
> + * fec_restart may sleep. can't call it in spin_lock
> + */
> + if (phy_dev->link)
> + fec_restart(ndev, phy_dev->duplex);
> phy_print_status(phy_dev);
> + }
> }
Don't complicate things unnecessarily. Just put a patch in front of this
one to remove the spinlock. As you removed it already from the RX and TX
paths it doesn't protect anything anymore.
>
> static int fec_enet_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
> @@ -1882,6 +1909,7 @@ fec_probe(struct platform_device *pdev)
> if (ret)
> goto failed_register;
>
> + INIT_DELAYED_WORK(&fep->delay_work, fec_enet_work);
> return 0;
>
> failed_register:
> @@ -1918,6 +1946,7 @@ fec_drv_remove(struct platform_device *pdev)
> struct resource *r;
> int i;
>
> + cancel_delayed_work_sync(&fep->delay_work);
> unregister_netdev(ndev);
> fec_enet_mii_remove(fep);
> del_timer_sync(&fep->time_keep);
> diff --git a/drivers/net/ethernet/freescale/fec.h b/drivers/net/ethernet/freescale/fec.h
> index eb43729..a367b21 100644
> --- a/drivers/net/ethernet/freescale/fec.h
> +++ b/drivers/net/ethernet/freescale/fec.h
> @@ -260,7 +260,8 @@ struct fec_enet_private {
> int hwts_rx_en;
> int hwts_tx_en;
> struct timer_list time_keep;
> -
> + struct delayed_work delay_work;
> + int timeout;
> };
>
> void fec_ptp_init(struct net_device *ndev, struct platform_device *pdev);
--
Pengutronix e.K. | Lucas Stach |
Industrial Linux Solutions | http://www.pengutronix.de/ |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-5076 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH 1/1 v2 net] net: fec: fix kernel oops when plug/unplug cable many times
2013-04-28 3:08 [PATCH 1/1 v2 net] net: fec: fix kernel oops when plug/unplug cable many times Frank Li
2013-04-29 13:47 ` Lucas Stach
@ 2013-04-30 19:35 ` David Miller
1 sibling, 0 replies; 4+ messages in thread
From: David Miller @ 2013-04-30 19:35 UTC (permalink / raw)
To: Frank.Li; +Cc: romieu, r.schwebel, l.stach, netdev, festevam, shawn.guo, lznuaa
From: Frank Li <Frank.Li@freescale.com>
Date: Sun, 28 Apr 2013 11:08:28 +0800
> @@ -403,6 +403,12 @@ fec_restart(struct net_device *ndev, int duplex)
> const struct platform_device_id *id_entry =
> platform_get_device_id(fep->pdev);
> int i;
> + if (netif_running(ndev)) {
> + napi_disable(&fep->napi);
> + netif_stop_queue(ndev);
> + netif_tx_lock(ndev);
> + }
> +
> u32 temp_mac[2];
> u32 rcntl = OPT_FRAME_SIZE | 0x04;
> u32 ecntl = 0x2; /* ETHEREN */
Please don't put real statements in the middle of function variable
declarations.
Thanks.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH 1/1 v2 net] net: fec: fix kernel oops when plug/unplug cable many times
2013-04-29 13:47 ` Lucas Stach
@ 2013-05-02 2:08 ` Frank Li
0 siblings, 0 replies; 4+ messages in thread
From: Frank Li @ 2013-05-02 2:08 UTC (permalink / raw)
To: Lucas Stach
Cc: Frank Li, Francois Romieu, Robert Schwebel, David Miller, netdev,
Fabio Estevam, Shawn Guo
2013/4/29 Lucas Stach <l.stach@pengutronix.de>:
> Hi Frank,
>
> Am Sonntag, den 28.04.2013, 11:08 +0800 schrieb Frank Li:
>> reproduce steps
>> 1. flood ping from other machine
>> ping -f -s 41000 IP
>> 2. run below script
>> while [ 1 ]; do ethtool -s eth0 autoneg off;
>> sleep 3;ethtool -s eth0 autoneg on; sleep 4; done;
>>
>> You can see oops in one hour.
>>
>> The reason is fec_restart clear BD but NAPI may use it.
>> The solution is disable NAPI and stop xmit when reset BD.
>> disable NAPI may sleep, so fec_restart can't be call in
>> atomic context.
>>
>> Signed-off-by: Frank Li <Frank.Li@freescale.com>
>> ---
>>
>> Change from V1 to V2
>> Add netif_tx_lock(ndev) to avoid xmit runing when reset hardware
>>
>> drivers/net/ethernet/freescale/fec.c | 41 +++++++++++++++++++++++++++++-----
>> drivers/net/ethernet/freescale/fec.h | 3 +-
>> 2 files changed, 37 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/freescale/fec.c b/drivers/net/ethernet/freescale/fec.c
>> index 73195f6..d140b50 100644
>> --- a/drivers/net/ethernet/freescale/fec.c
>> +++ b/drivers/net/ethernet/freescale/fec.c
>> @@ -403,6 +403,12 @@ fec_restart(struct net_device *ndev, int duplex)
>> const struct platform_device_id *id_entry =
>> platform_get_device_id(fep->pdev);
>> int i;
>> + if (netif_running(ndev)) {
>> + napi_disable(&fep->napi);
>> + netif_stop_queue(ndev);
>> + netif_tx_lock(ndev);
>> + }
>> +
>> u32 temp_mac[2];
>> u32 rcntl = OPT_FRAME_SIZE | 0x04;
>> u32 ecntl = 0x2; /* ETHEREN */
>> @@ -559,6 +565,12 @@ fec_restart(struct net_device *ndev, int duplex)
>>
>> /* Enable interrupts we wish to service */
>> writel(FEC_DEFAULT_IMASK, fep->hwp + FEC_IMASK);
>> +
>> + if (netif_running(ndev)) {
>> + napi_enable(&fep->napi);
>> + netif_wake_queue(ndev);
>> + netif_tx_unlock(ndev);
>> + }
>> }
>>
>> static void
>> @@ -598,8 +610,20 @@ fec_timeout(struct net_device *ndev)
>>
>> ndev->stats.tx_errors++;
>>
>> - fec_restart(ndev, fep->full_duplex);
>> - netif_wake_queue(ndev);
>> + fep->timeout = 1;
>> + schedule_delayed_work(&fep->delay_work, msecs_to_jiffies(1));
>> +}
>
> Why are you using delayed work here? I don't see a reason why we would
> like to defer execution here. Just use schedule_work().
>
There are a silicon bug, which need delay work to workaround it.
So we can share a delay work in future.
>> +
>> +static void fec_enet_work(struct work_struct *work)
>> +{
>> + struct fec_enet_private *fep =
>> + container_of(work, struct fec_enet_private, delay_work.work);
>> +
>> + if (fep->timeout) {
>> + fep->timeout = 0;
>> + fec_restart(fep->netdev, fep->full_duplex);
>> + netif_wake_queue(fep->netdev);
>> + }
>> }
>>
>> static void
>> @@ -996,9 +1020,6 @@ static void fec_enet_adjust_link(struct net_device *ndev)
>> status_change = 1;
>> }
>>
>> - /* if any of the above changed restart the FEC */
>> - if (status_change)
>> - fec_restart(ndev, phy_dev->duplex);
>> } else {
>> if (fep->link) {
>> fec_stop(ndev);
>> @@ -1010,8 +1031,14 @@ static void fec_enet_adjust_link(struct net_device *ndev)
>> spin_unlock:
>> spin_unlock_irqrestore(&fep->hw_lock, flags);
>>
>> - if (status_change)
>> + if (status_change) {
>> + /* if any of the above changed restart the FEC,
>> + * fec_restart may sleep. can't call it in spin_lock
>> + */
>> + if (phy_dev->link)
>> + fec_restart(ndev, phy_dev->duplex);
>> phy_print_status(phy_dev);
>> + }
>> }
>
> Don't complicate things unnecessarily. Just put a patch in front of this
> one to remove the spinlock. As you removed it already from the RX and TX
> paths it doesn't protect anything anymore.
>
>>
>> static int fec_enet_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
>> @@ -1882,6 +1909,7 @@ fec_probe(struct platform_device *pdev)
>> if (ret)
>> goto failed_register;
>>
>> + INIT_DELAYED_WORK(&fep->delay_work, fec_enet_work);
>> return 0;
>>
>> failed_register:
>> @@ -1918,6 +1946,7 @@ fec_drv_remove(struct platform_device *pdev)
>> struct resource *r;
>> int i;
>>
>> + cancel_delayed_work_sync(&fep->delay_work);
>> unregister_netdev(ndev);
>> fec_enet_mii_remove(fep);
>> del_timer_sync(&fep->time_keep);
>> diff --git a/drivers/net/ethernet/freescale/fec.h b/drivers/net/ethernet/freescale/fec.h
>> index eb43729..a367b21 100644
>> --- a/drivers/net/ethernet/freescale/fec.h
>> +++ b/drivers/net/ethernet/freescale/fec.h
>> @@ -260,7 +260,8 @@ struct fec_enet_private {
>> int hwts_rx_en;
>> int hwts_tx_en;
>> struct timer_list time_keep;
>> -
>> + struct delayed_work delay_work;
>> + int timeout;
>> };
>>
>> void fec_ptp_init(struct net_device *ndev, struct platform_device *pdev);
>
> --
> Pengutronix e.K. | Lucas Stach |
> Industrial Linux Solutions | http://www.pengutronix.de/ |
> Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-5076 |
> Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
>
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2013-05-02 2:08 UTC | newest]
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2013-04-28 3:08 [PATCH 1/1 v2 net] net: fec: fix kernel oops when plug/unplug cable many times Frank Li
2013-04-29 13:47 ` Lucas Stach
2013-05-02 2:08 ` Frank Li
2013-04-30 19:35 ` David Miller
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