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ath9k: fix an rx descriptor processing race condition

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Signed-off-by: Felix Fietkau <nbd@openwrt.org>

SVN-Revision: 37746
This commit is contained in:
Felix Fietkau 2013-08-10 14:00:33 +00:00
parent 007bd290ea
commit fd586c0275
1 changed files with 82 additions and 0 deletions
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82
package/kernel/mac80211/patches/556-ath9k_fix_rx_race.patch Normal file
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@ -0,0 +1,82 @@
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -79,10 +79,6 @@ struct ath_config {
sizeof(struct ath_buf_state)); \
} while (0)
-#define ATH_RXBUF_RESET(_bf) do { \
- (_bf)->bf_stale = false; \
- } while (0)
-
/**
* enum buffer_type - Buffer type flags
*
@@ -315,6 +311,7 @@ struct ath_rx {
struct ath_descdma rxdma;
struct ath_rx_edma rx_edma[ATH9K_RX_QUEUE_MAX];
+ struct ath_buf *buf_hold;
struct sk_buff *frag;
u32 ampdu_ref;
--- a/drivers/net/wireless/ath/ath9k/recv.c
+++ b/drivers/net/wireless/ath/ath9k/recv.c
@@ -42,8 +42,6 @@ static void ath_rx_buf_link(struct ath_s
struct ath_desc *ds;
struct sk_buff *skb;
- ATH_RXBUF_RESET(bf);
-
ds = bf->bf_desc;
ds->ds_link = 0; /* link to null */
ds->ds_data = bf->bf_buf_addr;
@@ -70,6 +68,14 @@ static void ath_rx_buf_link(struct ath_s
sc->rx.rxlink = &ds->ds_link;
}
+static void ath_rx_buf_relink(struct ath_softc *sc, struct ath_buf *bf)
+{
+ if (sc->rx.buf_hold)
+ ath_rx_buf_link(sc, sc->rx.buf_hold);
+
+ sc->rx.buf_hold = bf;
+}
+
static void ath_setdefantenna(struct ath_softc *sc, u32 antenna)
{
/* XXX block beacon interrupts */
@@ -117,7 +123,6 @@ static bool ath_rx_edma_buf_link(struct
skb = bf->bf_mpdu;
- ATH_RXBUF_RESET(bf);
memset(skb->data, 0, ah->caps.rx_status_len);
dma_sync_single_for_device(sc->dev, bf->bf_buf_addr,
ah->caps.rx_status_len, DMA_TO_DEVICE);
@@ -432,6 +437,7 @@ int ath_startrecv(struct ath_softc *sc)
if (list_empty(&sc->rx.rxbuf))
goto start_recv;
+ sc->rx.buf_hold = NULL;
sc->rx.rxlink = NULL;
list_for_each_entry_safe(bf, tbf, &sc->rx.rxbuf, list) {
ath_rx_buf_link(sc, bf);
@@ -677,6 +683,9 @@ static struct ath_buf *ath_get_next_rx_b
}
bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
+ if (bf == sc->rx.buf_hold)
+ return NULL;
+
ds = bf->bf_desc;
/*
@@ -1391,7 +1400,7 @@ requeue:
if (edma) {
ath_rx_edma_buf_link(sc, qtype);
} else {
- ath_rx_buf_link(sc, bf);
+ ath_rx_buf_relink(sc, bf);
ath9k_hw_rxena(ah);
}
} while (1);