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| author | Xie He <xie.he.0141@gmail.com> | 2021-03-07 14:33:07 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-03-17 19:03:36 +0300 |
| commit | 11a589205119b7466245ccd6815a8bf3180adae0 (patch) | |
| tree | 5db88e1761dc33d9de00c02eb414d6b0f262fb9d | |
| parent | b4800e7a1c9f80a1a0e417ab36a1da4959f8b399 (diff) | |
| download | linux-11a589205119b7466245ccd6815a8bf3180adae0.tar.xz | |
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>
| -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 709e3de0f6af..60f357d2f79f 100644 --- a/drivers/net/wan/lapbether.c +++ b/drivers/net/wan/lapbether.c @@ -283,7 +283,6 @@ static int lapbeth_open(struct net_device *dev) return -ENODEV; } - netif_start_queue(dev); return 0; } @@ -291,8 +290,6 @@ 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); |