X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=Documentation%2Fnetworking%2Fnetdevices.txt;h=847cedb238f6c0ed24ad6568b1d440bc3843fc6f;hb=97bf2856c6014879bd04983a3e9dfcdac1e7fe85;hp=8c456edb6aadef6615e27df83d594b6efad6d85e;hpb=5273a3df6485dc2ad6aa7ddd441b9a21970f003b;p=linux-2.6.git

diff --git a/Documentation/networking/netdevices.txt b/Documentation/networking/netdevices.txt
index 8c456edb6..847cedb23 100644
--- a/Documentation/networking/netdevices.txt
+++ b/Documentation/networking/netdevices.txt
@@ -42,17 +42,32 @@ dev->get_stats:
 	Context: nominally process, but don't sleep inside an rwlock
 
 dev->hard_start_xmit:
-	Synchronization: dev->xmit_lock spinlock.
+	Synchronization: netif_tx_lock spinlock.
+	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 -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
+               Interrupts must be enabled when calling hard_start_xmit.
+                (Interrupts must also be enabled when enabling the BH handler.)
+	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.
+	Synchronization: netif_tx_lock spinlock.
 	Context: BHs disabled
 	Notes: netif_queue_stopped() is guaranteed true
 
 dev->set_multicast_list:
-	Synchronization: dev->xmit_lock spinlock.
+	Synchronization: netif_tx_lock spinlock.
 	Context: BHs disabled
 
 dev->poll: