We would get an oops on RX on -ENOMEM by passing
NULL to the hardware on ath_rx_buf_link(). The oops
would look something like this:
ath_rx_tasklet
...
RIP: ath_rx_buf_link
We correct this by handling the allocation for the next
skb we will put in our RX tail directly on the ath_rx_tasklet()
*prior* to sending up the last hardware processed
skb. If we run out of memory this gauranteees we have
skbs to work with while it simply drops new received
frames.
Signed-off-by: Luis R. Rodriguez <lrodriguez@xxxxxxxxxxx>
---
drivers/net/wireless/ath9k/recv.c | 18 ++++++++++++++----
1 files changed, 14 insertions(+), 4 deletions(-)
diff --git a/drivers/net/wireless/ath9k/recv.c b/drivers/net/wireless/ath9k/recv.c
index 0941589..a4f92b2 100644
--- a/drivers/net/wireless/ath9k/recv.c
+++ b/drivers/net/wireless/ath9k/recv.c
@@ -441,18 +441,16 @@ static void ath_rx_requeue(struct ath_softc *sc, struct sk_buff *skb)
*/
static int ath_rx_indicate(struct ath_softc *sc,
struct sk_buff *skb,
+ struct sk_buff *nskb,
struct ath_recv_status *status,
u16 keyix)
{
struct ath_buf *bf = ATH_RX_CONTEXT(skb)->ctx_rxbuf;
- struct sk_buff *nskb;
int type;
/* indicate frame to the stack, which will free the old skb. */
type = ath__rx_indicate(sc, skb, status, keyix);
- /* allocate a new skb and queue it to for H/W processing */
- nskb = ath_rxbuf_alloc(sc, sc->sc_rxbufsize);
if (nskb != NULL) {
bf->bf_mpdu = nskb;
bf->bf_buf_addr = ath_skb_map_single(sc,
@@ -741,6 +739,7 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush)
struct ath_desc *ds;
struct ieee80211_hdr *hdr;
struct sk_buff *skb = NULL;
+ struct sk_buff *nskb = NULL;
struct ath_recv_status rx_status;
struct ath_hal *ah = sc->sc_ah;
int type, rx_processed = 0;
@@ -963,6 +962,17 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush)
*/
if (sc->sc_rxbufsize < ds->ds_rxstat.rs_datalen)
goto rx_next;
+
+ /* allocate a new skb and queue it to for H/W processing */
+ nskb = ath_rxbuf_alloc(sc, sc->sc_rxbufsize);
+
+ /* Diregard current RX'd frame and reuse the old skb */
+ if (!nskb) {
+ list_move_tail(&bf->list, &sc->sc_rxbuf);
+ ath_rx_buf_link(sc, bf);
+ goto rx_next;
+ }
+
/*
* Sync and unmap the frame. At this point we're
* committed to passing the sk_buff somewhere so
@@ -1052,7 +1062,7 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush)
/* Pass frames up to the stack. */
- type = ath_rx_indicate(sc, skb,
+ type = ath_rx_indicate(sc, skb, nskb,
&rx_status, ds->ds_rxstat.rs_keyix);
/*
--
1.5.6.rc2.15.g457bb.dirty
--
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