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| author | Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> | 2013-09-04 02:41:27 +0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-09-04 14:55:34 -0400 |
| commit | d2779e99468fd83ef1493c34f3803fec9aad8345 (patch) | |
| tree | 4b240a6296af57e1340a68c37df65fd43ee861dc /drivers/net | |
| parent | 3a1c756590633c0e86df606e5c618c190926a0df (diff) | |
| download | linux-d2779e99468fd83ef1493c34f3803fec9aad8345.tar.gz linux-d2779e99468fd83ef1493c34f3803fec9aad8345.tar.bz2 linux-d2779e99468fd83ef1493c34f3803fec9aad8345.zip | |
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')
| -rw-r--r-- | drivers/net/ethernet/renesas/sh_eth.c | 12 |
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); |