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authorSergei Shtylyov <sergei.shtylyov@cogentembedded.com>2013-09-04 02:41:27 +0400
committerDavid S. Miller <davem@davemloft.net>2013-09-04 22:55:34 +0400
commitd2779e99468fd83ef1493c34f3803fec9aad8345 (patch)
tree4b240a6296af57e1340a68c37df65fd43ee861dc /drivers/net/ethernet/renesas
parent3a1c756590633c0e86df606e5c618c190926a0df (diff)
downloadlinux-d2779e99468fd83ef1493c34f3803fec9aad8345.tar.xz
sh_eth: fix napi_{en|dis}able() calls racing against interrupts
While implementing NAPI for the driver, I overlooked the race conditions where interrupt handler might have called napi_schedule_prep() before napi_enable() was called or after napi_disable() was called. If RX interrupt happens, this would cause the endless interrupts and messages like: sh-eth eth0: ignoring interrupt, status 0x00040000, mask 0x01ff009f. The interrupt wouldn't even be masked by the kernel eventually since the handler would return IRQ_HANDLED all the time. As a fix, move napi_enable() call before request_irq() call and napi_disable() call after free_irq() call. Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/renesas')
-rw-r--r--drivers/net/ethernet/renesas/sh_eth.c12
1 files changed, 7 insertions, 5 deletions
diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c
index 1ccd5959c0bf..3426d32a1803 100644
--- a/drivers/net/ethernet/renesas/sh_eth.c
+++ b/drivers/net/ethernet/renesas/sh_eth.c
@@ -1857,11 +1857,13 @@ static int sh_eth_open(struct net_device *ndev)
pm_runtime_get_sync(&mdp->pdev->dev);
+ napi_enable(&mdp->napi);
+
ret = request_irq(ndev->irq, sh_eth_interrupt,
mdp->cd->irq_flags, ndev->name, ndev);
if (ret) {
dev_err(&ndev->dev, "Can not assign IRQ number\n");
- return ret;
+ goto out_napi_off;
}
/* Descriptor set */
@@ -1879,12 +1881,12 @@ static int sh_eth_open(struct net_device *ndev)
if (ret)
goto out_free_irq;
- napi_enable(&mdp->napi);
-
return ret;
out_free_irq:
free_irq(ndev->irq, ndev);
+out_napi_off:
+ napi_disable(&mdp->napi);
pm_runtime_put_sync(&mdp->pdev->dev);
return ret;
}
@@ -1976,8 +1978,6 @@ static int sh_eth_close(struct net_device *ndev)
{
struct sh_eth_private *mdp = netdev_priv(ndev);
- napi_disable(&mdp->napi);
-
netif_stop_queue(ndev);
/* Disable interrupts by clearing the interrupt mask. */
@@ -1995,6 +1995,8 @@ static int sh_eth_close(struct net_device *ndev)
free_irq(ndev->irq, ndev);
+ napi_disable(&mdp->napi);
+
/* Free all the skbuffs in the Rx queue. */
sh_eth_ring_free(ndev);