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| author | Sowmini Varadhan <sowmini.varadhan@oracle.com> | 2014-08-13 16:29:41 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-08-14 05:04:46 +0200 |
| commit | 1d311ad2f9fe5d75cf228372174170d0f435e3ef (patch) | |
| tree | e1ceb11d8f5ea8602b970baac8475735dd88eda9 | |
| parent | sunvnet: Do not spin in an infinite loop when vio_ldc_send() returns EAGAIN (diff) | |
| download | linux-1d311ad2f9fe5d75cf228372174170d0f435e3ef.tar.xz linux-1d311ad2f9fe5d75cf228372174170d0f435e3ef.zip | |
sunvnet: Schedule maybe_tx_wakeup() as a tasklet from ldc_rx path
At the tail of vnet_event(), if we hit the maybe_tx_wakeup()
condition, we try to take the netif_tx_lock() in the
recv-interrupt-context and can deadlock with dev_watchdog().
vnet_event() should schedule maybe_tx_wakeup() as a tasklet
to avoid this deadlock
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/ethernet/sun/sunvnet.c | 12 | ||||
| -rw-r--r-- | drivers/net/ethernet/sun/sunvnet.h | 4 |
2 files changed, 14 insertions, 2 deletions
diff --git a/drivers/net/ethernet/sun/sunvnet.c b/drivers/net/ethernet/sun/sunvnet.c index a5871791e452..23c89ab5a6ad 100644 --- a/drivers/net/ethernet/sun/sunvnet.c +++ b/drivers/net/ethernet/sun/sunvnet.c @@ -488,8 +488,9 @@ static int handle_mcast(struct vnet_port *port, void *msgbuf) return 0; } -static void maybe_tx_wakeup(struct vnet *vp) +static void maybe_tx_wakeup(unsigned long param) { + struct vnet *vp = (struct vnet *)param; struct net_device *dev = vp->dev; netif_tx_lock(dev); @@ -586,8 +587,13 @@ static void vnet_event(void *arg, int event) break; } spin_unlock(&vio->lock); + /* Kick off a tasklet to wake the queue. We cannot call + * maybe_tx_wakeup directly here because we could deadlock on + * netif_tx_lock() with dev_watchdog() + */ if (unlikely(tx_wakeup && err != -ECONNRESET)) - maybe_tx_wakeup(port->vp); + tasklet_schedule(&port->vp->vnet_tx_wakeup); + local_irq_restore(flags); } @@ -1070,6 +1076,7 @@ static struct vnet *vnet_new(const u64 *local_mac) vp = netdev_priv(dev); spin_lock_init(&vp->lock); + tasklet_init(&vp->vnet_tx_wakeup, maybe_tx_wakeup, (unsigned long)vp); vp->dev = dev; INIT_LIST_HEAD(&vp->port_list); @@ -1129,6 +1136,7 @@ static void vnet_cleanup(void) vp = list_first_entry(&vnet_list, struct vnet, list); list_del(&vp->list); dev = vp->dev; + tasklet_kill(&vp->vnet_tx_wakeup); /* vio_unregister_driver() should have cleaned up port_list */ BUG_ON(!list_empty(&vp->port_list)); unregister_netdev(dev); diff --git a/drivers/net/ethernet/sun/sunvnet.h b/drivers/net/ethernet/sun/sunvnet.h index d347a5bf24b0..de5c2c64996f 100644 --- a/drivers/net/ethernet/sun/sunvnet.h +++ b/drivers/net/ethernet/sun/sunvnet.h @@ -1,6 +1,8 @@ #ifndef _SUNVNET_H #define _SUNVNET_H +#include <linux/interrupt.h> + #define DESC_NCOOKIES(entry_size) \ ((entry_size) - sizeof(struct vio_net_desc)) @@ -78,6 +80,8 @@ struct vnet { struct list_head list; u64 local_mac; + + struct tasklet_struct vnet_tx_wakeup; }; #endif /* _SUNVNET_H */ |