Skip to content

Commit

Permalink
doc, net: Update netdev operation names
Browse files Browse the repository at this point in the history
Commits d314774 ('netdev: network
device operations infrastructure') and
0082982 ('netdev: add more functions
to netdevice ops') moved and renamed net device operation pointers.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
  • Loading branch information
Ben Hutchings authored and David S. Miller committed Apr 6, 2012
1 parent 04fd3d3 commit b3cf654
Show file tree
Hide file tree
Showing 2 changed files with 14 additions and 14 deletions.
12 changes: 6 additions & 6 deletions Documentation/networking/driver.txt
Original file line number Diff line number Diff line change
Expand Up @@ -2,7 +2,7 @@ Document about softnet driver issues

Transmit path guidelines:

1) The hard_start_xmit method must never return '1' under any
1) The ndo_start_xmit method must never return '1' under any
normal circumstances. It is considered a hard error unless
there is no way your device can tell ahead of time when it's
transmit function will become busy.
Expand Down Expand Up @@ -61,10 +61,10 @@ Transmit path guidelines:
2) Do not forget to update netdev->trans_start to jiffies after
each new tx packet is given to the hardware.

3) A hard_start_xmit method must not modify the shared parts of a
3) An ndo_start_xmit method must not modify the shared parts of a
cloned SKB.

4) Do not forget that once you return 0 from your hard_start_xmit
4) Do not forget that once you return 0 from your ndo_start_xmit
method, it is your driver's responsibility to free up the SKB
and in some finite amount of time.

Expand All @@ -74,7 +74,7 @@ Transmit path guidelines:
This error can deadlock sockets waiting for send buffer room
to be freed up.

If you return 1 from the hard_start_xmit method, you must not keep
If you return 1 from the ndo_start_xmit method, you must not keep
any reference to that SKB and you must not attempt to free it up.

Probing guidelines:
Expand All @@ -85,10 +85,10 @@ Probing guidelines:

Close/stop guidelines:

1) After the dev->stop routine has been called, the hardware must
1) After the ndo_stop routine has been called, the hardware must
not receive or transmit any data. All in flight packets must
be aborted. If necessary, poll or wait for completion of
any reset commands.

2) The dev->stop routine will be called by unregister_netdevice
2) The ndo_stop routine will be called by unregister_netdevice
if device is still UP.
16 changes: 8 additions & 8 deletions Documentation/networking/netdevices.txt
Original file line number Diff line number Diff line change
Expand Up @@ -47,24 +47,24 @@ packets is preferred.

struct net_device synchronization rules
=======================================
dev->open:
ndo_open:
Synchronization: rtnl_lock() semaphore.
Context: process

dev->stop:
ndo_stop:
Synchronization: rtnl_lock() semaphore.
Context: process
Note: netif_running() is guaranteed false

dev->do_ioctl:
ndo_do_ioctl:
Synchronization: rtnl_lock() semaphore.
Context: process

dev->get_stats:
ndo_get_stats:
Synchronization: dev_base_lock rwlock.
Context: nominally process, but don't sleep inside an rwlock

dev->hard_start_xmit:
ndo_start_xmit:
Synchronization: __netif_tx_lock spinlock.

When the driver sets NETIF_F_LLTX in dev->features this will be
Expand All @@ -86,20 +86,20 @@ dev->hard_start_xmit:
o NETDEV_TX_LOCKED Locking failed, please retry quickly.
Only valid when NETIF_F_LLTX is set.

dev->tx_timeout:
ndo_tx_timeout:
Synchronization: netif_tx_lock spinlock; all TX queues frozen.
Context: BHs disabled
Notes: netif_queue_stopped() is guaranteed true

dev->set_rx_mode:
ndo_set_rx_mode:
Synchronization: netif_addr_lock spinlock.
Context: BHs disabled

struct napi_struct synchronization rules
========================================
napi->poll:
Synchronization: NAPI_STATE_SCHED bit in napi->state. Device
driver's dev->close method will invoke napi_disable() on
driver's ndo_stop method will invoke napi_disable() on
all NAPI instances which will do a sleeping poll on the
NAPI_STATE_SCHED napi->state bit, waiting for all pending
NAPI activity to cease.
Expand Down

0 comments on commit b3cf654

Please sign in to comment.