Defer allocation of the actual receive mbuf until the external buffer

is returned from the card to the driver. Add a counter that shows
how many times this allocation has failed. Note, that we could even
further delay the allocation of the mbuf until we know, that we need it
(there are no receive errors and the connection is open). This will be done
in a later commit.

Print the new statistics field in atmconfig.

1 files changed, 4 insertions, 0 deletions

diff --git a/sys/dev/hatm/if_hatm_rx.c b/sys/dev/hatm/if_hatm_rx.c
index 15e568d..f42e821 100644
--- a/sys/dev/hatm/if_hatm_rx.c
+++ b/sys/dev/hatm/if_hatm_rx.c
@@ -116,6 +116,10 @@ hatm_rx(struct hatm_softc *sc, u_int cid, u_int flags, struct mbuf *m0,
 		}
 		goto drop;
 	}
+	if (m0 == NULL) {
+		sc->istats.no_rcv_mbuf++;
+		return;
+	}
 
 	if ((m0->m_len = len) == 0) {
 		sc->istats.empty_hbuf++;