diff options
| author | Xie He <xie.he.0141@gmail.com> | 2021-03-07 03:33:07 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-03-17 16:34:29 +0100 |
| commit | e054e4b54821e2c19b056060ac04a195ad69a7b2 (patch) | |
| tree | 5a9d9d22dcb66cdf833d63db27b9b150736f9c80 /drivers/net | |
| parent | ab44f7317c16ddcf9ee12ba2aca60771266c2dc6 (diff) | |
net: lapbether: Remove netif_start_queue / netif_stop_queue
commit f7d9d4854519fdf4d45c70a4d953438cd88e7e58 upstream.
For the devices in this driver, the default qdisc is "noqueue",
because their "tx_queue_len" is 0.
In function "__dev_queue_xmit" in "net/core/dev.c", devices with the
"noqueue" qdisc are specially handled. Packets are transmitted without
being queued after a "dev->flags & IFF_UP" check. However, it's possible
that even if this check succeeds, "ops->ndo_stop" may still have already
been called. This is because in "__dev_close_many", "ops->ndo_stop" is
called before clearing the "IFF_UP" flag.
If we call "netif_stop_queue" in "ops->ndo_stop", then it's possible in
"__dev_queue_xmit", it sees the "IFF_UP" flag is present, and then it
checks "netif_xmit_stopped" and finds that the queue is already stopped.
In this case, it will complain that:
"Virtual device ... asks to queue packet!"
To prevent "__dev_queue_xmit" from generating this complaint, we should
not call "netif_stop_queue" in "ops->ndo_stop".
We also don't need to call "netif_start_queue" in "ops->ndo_open",
because after a netdev is allocated and registered, the
"__QUEUE_STATE_DRV_XOFF" flag is initially not set, so there is no need
to call "netif_start_queue" to clear it.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Xie He <xie.he.0141@gmail.com>
Acked-by: Martin Schiller <ms@dev.tdt.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/net')
| -rw-r--r-- | drivers/net/wan/lapbether.c | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/drivers/net/wan/lapbether.c b/drivers/net/wan/lapbether.c index e5fc1b95cea6..fad5fc8b9edb 100644 --- a/drivers/net/wan/lapbether.c +++ b/drivers/net/wan/lapbether.c @@ -286,7 +286,6 @@ static int lapbeth_open(struct net_device *dev) return -ENODEV; } - netif_start_queue(dev); return 0; } @@ -294,8 +293,6 @@ static int lapbeth_close(struct net_device *dev) { int err; - netif_stop_queue(dev); - if ((err = lapb_unregister(dev)) != LAPB_OK) pr_err("lapb_unregister error: %d\n", err); |