net: remove NETDEV_TX_LOCKED support

No more users in the tree, remove NETDEV_TX_LOCKED support.
Adds another hole in softnet_stats struct, but better than keeping
the unused collision counter around.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 7 insertions, 12 deletions

diff --git a/Documentation/networking/netdev-features.txt b/Documentation/networking/netdev-features.txt
index f310edec8a77..7413eb05223b 100644
--- a/Documentation/networking/netdev-features.txt
+++ b/Documentation/networking/netdev-features.txt
@@ -131,13 +131,11 @@ stack. Driver should not change behaviour based on them.
 
  * LLTX driver (deprecated for hardware drivers)
 
-NETIF_F_LLTX should be set in drivers that implement their own locking in
-transmit path or don't need locking at all (e.g. software tunnels).
-In ndo_start_xmit, it is recommended to use a try_lock and return
-NETDEV_TX_LOCKED when the spin lock fails.  The locking should also properly
-protect against other callbacks (the rules you need to find out).
+NETIF_F_LLTX is meant to be used by drivers that don't need locking at all,
+e.g. software tunnels.
 
-Don't use it for new drivers.
+This is also used in a few legacy drivers that implement their
+own locking, don't use it for new (hardware) drivers.
 
  * netns-local device
 
diff --git a/Documentation/networking/netdevices.txt b/Documentation/networking/netdevices.txt
index 0b1cf6b2a592..7fec2061a334 100644
--- a/Documentation/networking/netdevices.txt
+++ b/Documentation/networking/netdevices.txt
@@ -69,10 +69,9 @@ ndo_start_xmit:
 
         When the driver sets NETIF_F_LLTX in dev->features this will be
         called without holding netif_tx_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 NETDEV_TX_LOCKED when the spin lock fails.
-        The locking there should also properly protect against 
-        set_rx_mode. Note that the use of NETIF_F_LLTX is deprecated.
+        has to lock by itself when needed.
+        The locking there should also properly protect against
+        set_rx_mode. WARNING: use of NETIF_F_LLTX is deprecated.
         Don't use it for new drivers.
 
         Context: Process with BHs disabled or BH (timer),
@@ -83,8 +82,6 @@ ndo_start_xmit:
         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.
 
 ndo_tx_timeout:
         Synchronization: netif_tx_lock spinlock; all TX queues frozen.