Commit 7066e0b7 authored by Andi Kleen's avatar Andi Kleen Committed by David S. Miller

[NET]: Improve netdev->hard_start_xmit() documentation.

With improvements by Francois Romieu and David
S. Miller.
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 94ca8643
......@@ -43,8 +43,21 @@ dev->get_stats:
dev->hard_start_xmit:
Synchronization: dev->xmit_lock spinlock.
When the driver sets NETIF_F_LLTX in dev->features this will be
called without holding xmit_lock. In this case the driver
has to lock by itself when needed. It is recommended to use a try lock
for this and return -1 when the spin lock fails.
The locking there should also properly protect against
set_multicast_list
Context: BHs disabled
Notes: netif_queue_stopped() is guaranteed false
Return codes:
o NETDEV_TX_OK everything ok.
o NETDEV_TX_BUSY Cannot transmit packet, try later
Usually a bug, means queue start/stop flow control is broken in
the driver. Note: the driver must NOT put the skb in its DMA ring.
o NETDEV_TX_LOCKED Locking failed, please retry quickly.
Only valid when NETIF_F_LLTX is set.
dev->tx_timeout:
Synchronization: dev->xmit_lock spinlock.
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment