Commit d2779e99 authored by Sergei Shtylyov's avatar Sergei Shtylyov Committed by David S. Miller

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: default avatarSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 3a1c7565
...@@ -1857,11 +1857,13 @@ static int sh_eth_open(struct net_device *ndev) ...@@ -1857,11 +1857,13 @@ static int sh_eth_open(struct net_device *ndev)
pm_runtime_get_sync(&mdp->pdev->dev); pm_runtime_get_sync(&mdp->pdev->dev);
napi_enable(&mdp->napi);
ret = request_irq(ndev->irq, sh_eth_interrupt, ret = request_irq(ndev->irq, sh_eth_interrupt,
mdp->cd->irq_flags, ndev->name, ndev); mdp->cd->irq_flags, ndev->name, ndev);
if (ret) { if (ret) {
dev_err(&ndev->dev, "Can not assign IRQ number\n"); dev_err(&ndev->dev, "Can not assign IRQ number\n");
return ret; goto out_napi_off;
} }
/* Descriptor set */ /* Descriptor set */
...@@ -1879,12 +1881,12 @@ static int sh_eth_open(struct net_device *ndev) ...@@ -1879,12 +1881,12 @@ static int sh_eth_open(struct net_device *ndev)
if (ret) if (ret)
goto out_free_irq; goto out_free_irq;
napi_enable(&mdp->napi);
return ret; return ret;
out_free_irq: out_free_irq:
free_irq(ndev->irq, ndev); free_irq(ndev->irq, ndev);
out_napi_off:
napi_disable(&mdp->napi);
pm_runtime_put_sync(&mdp->pdev->dev); pm_runtime_put_sync(&mdp->pdev->dev);
return ret; return ret;
} }
...@@ -1976,8 +1978,6 @@ static int sh_eth_close(struct net_device *ndev) ...@@ -1976,8 +1978,6 @@ static int sh_eth_close(struct net_device *ndev)
{ {
struct sh_eth_private *mdp = netdev_priv(ndev); struct sh_eth_private *mdp = netdev_priv(ndev);
napi_disable(&mdp->napi);
netif_stop_queue(ndev); netif_stop_queue(ndev);
/* Disable interrupts by clearing the interrupt mask. */ /* Disable interrupts by clearing the interrupt mask. */
...@@ -1995,6 +1995,8 @@ static int sh_eth_close(struct net_device *ndev) ...@@ -1995,6 +1995,8 @@ static int sh_eth_close(struct net_device *ndev)
free_irq(ndev->irq, ndev); free_irq(ndev->irq, ndev);
napi_disable(&mdp->napi);
/* Free all the skbuffs in the Rx queue. */ /* Free all the skbuffs in the Rx queue. */
sh_eth_ring_free(ndev); sh_eth_ring_free(ndev);
......
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