* [PATCH 1/1] net: fec: fix kernel oops when plug/unplug cable many times
@ 2013-04-28 3:04 Frank Li
2013-04-28 20:11 ` Ben Hutchings
0 siblings, 1 reply; 2+ messages in thread
From: Frank Li @ 2013-04-28 3:04 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>
---
drivers/net/ethernet/freescale/fec.c | 39 ++++++++++++++++++++++++++++-----
drivers/net/ethernet/freescale/fec.h | 3 +-
2 files changed, 35 insertions(+), 7 deletions(-)
diff --git a/drivers/net/ethernet/freescale/fec.c b/drivers/net/ethernet/freescale/fec.c
index 73195f6..9128a3c 100644
--- a/drivers/net/ethernet/freescale/fec.c
+++ b/drivers/net/ethernet/freescale/fec.c
@@ -403,6 +403,11 @@ 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);
+ }
+
u32 temp_mac[2];
u32 rcntl = OPT_FRAME_SIZE | 0x04;
u32 ecntl = 0x2; /* ETHEREN */
@@ -559,6 +564,11 @@ 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);
+ }
}
static void
@@ -598,8 +608,20 @@ 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 +1018,6 @@ 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 +1029,14 @@ 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 +1907,7 @@ 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 +1944,7 @@ 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] 2+ messages in thread
* Re: [PATCH 1/1] net: fec: fix kernel oops when plug/unplug cable many times
2013-04-28 3:04 [PATCH 1/1] net: fec: fix kernel oops when plug/unplug cable many times Frank Li
@ 2013-04-28 20:11 ` Ben Hutchings
0 siblings, 0 replies; 2+ messages in thread
From: Ben Hutchings @ 2013-04-28 20:11 UTC (permalink / raw)
To: Frank Li
Cc: romieu, r.schwebel, davem, l.stach, netdev, festevam, shawn.guo, lznuaa
On Sun, 2013-04-28 at 11:04 +0800, Frank Li wrote:
> 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>
> ---
> drivers/net/ethernet/freescale/fec.c | 39 ++++++++++++++++++++++++++++-----
> drivers/net/ethernet/freescale/fec.h | 3 +-
> 2 files changed, 35 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/net/ethernet/freescale/fec.c b/drivers/net/ethernet/freescale/fec.c
> index 73195f6..9128a3c 100644
> --- a/drivers/net/ethernet/freescale/fec.c
> +++ b/drivers/net/ethernet/freescale/fec.c
> @@ -403,6 +403,11 @@ 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);
> + }
[...]
I would advise against calling netif_stop_queue() outside of the TX path
(for reasons explained in commit 29c69a488264). If you're sure the
carrier state is off at this point, it should be OK, though.
Ben.
--
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.
^ permalink raw reply [flat|nested] 2+ messages in thread
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2013-04-28 20:11 ` Ben Hutchings
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