Documentation: add networking driver's mapping error handling to DMA-API-HOWTO

Adds the concrete DMA mapping error handling for Networking drivers on the transmit path. Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation: add networking driver's mapping error handling to DMA-API-HOWTO
Adds the concrete DMA mapping error handling for Networking drivers on the transmit path. Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
FUJITA Tomonori · Linus Torvalds
1 parent 5fd75a7850
Showing 1 changed file with 5 additions and 0 deletions Side-by-side Diff
Documentation/DMA-API-HOWTO.txt
@@ -740,6 +740,11 @@
 		 */
 	}
  
+Networking drivers must call dev_kfree_skb to free the socket buffer
+and return NETDEV_TX_OK if the DMA mapping fails on the transmit hook
+(ndo_start_xmit). This means that the socket buffer is just dropped in
+the failure case.
+
 			   Closing
  
 This document, and the API itself, would not be in its current
...	...	@@ -740,6 +740,11 @@
740	740	*/
741	741	}
742	742
	743	+Networking drivers must call dev_kfree_skb to free the socket buffer
	744	+and return NETDEV_TX_OK if the DMA mapping fails on the transmit hook
	745	+(ndo_start_xmit). This means that the socket buffer is just dropped in
	746	+the failure case.
	747	+
743	748	Closing
744	749
745	750	This document, and the API itself, would not be in its current