ath9k: fix an rx descriptor processing race condition
[openwrt/svn-archive/archive.git] / package / mac80211 / patches / 556-ath9k_fix_rx_race.patch
1 --- a/drivers/net/wireless/ath/ath9k/ath9k.h
2 +++ b/drivers/net/wireless/ath/ath9k/ath9k.h
3 @@ -79,10 +79,6 @@ struct ath_config {
4 sizeof(struct ath_buf_state)); \
5 } while (0)
6
7 -#define ATH_RXBUF_RESET(_bf) do { \
8 - (_bf)->bf_stale = false; \
9 - } while (0)
10 -
11 /**
12 * enum buffer_type - Buffer type flags
13 *
14 @@ -317,6 +313,7 @@ struct ath_rx {
15 struct ath_descdma rxdma;
16 struct ath_rx_edma rx_edma[ATH9K_RX_QUEUE_MAX];
17
18 + struct ath_buf *buf_hold;
19 struct sk_buff *frag;
20
21 u32 ampdu_ref;
22 --- a/drivers/net/wireless/ath/ath9k/recv.c
23 +++ b/drivers/net/wireless/ath/ath9k/recv.c
24 @@ -42,8 +42,6 @@ static void ath_rx_buf_link(struct ath_s
25 struct ath_desc *ds;
26 struct sk_buff *skb;
27
28 - ATH_RXBUF_RESET(bf);
29 -
30 ds = bf->bf_desc;
31 ds->ds_link = 0; /* link to null */
32 ds->ds_data = bf->bf_buf_addr;
33 @@ -70,6 +68,14 @@ static void ath_rx_buf_link(struct ath_s
34 sc->rx.rxlink = &ds->ds_link;
35 }
36
37 +static void ath_rx_buf_relink(struct ath_softc *sc, struct ath_buf *bf)
38 +{
39 + if (sc->rx.buf_hold)
40 + ath_rx_buf_link(sc, sc->rx.buf_hold);
41 +
42 + sc->rx.buf_hold = bf;
43 +}
44 +
45 static void ath_setdefantenna(struct ath_softc *sc, u32 antenna)
46 {
47 /* XXX block beacon interrupts */
48 @@ -117,7 +123,6 @@ static bool ath_rx_edma_buf_link(struct
49
50 skb = bf->bf_mpdu;
51
52 - ATH_RXBUF_RESET(bf);
53 memset(skb->data, 0, ah->caps.rx_status_len);
54 dma_sync_single_for_device(sc->dev, bf->bf_buf_addr,
55 ah->caps.rx_status_len, DMA_TO_DEVICE);
56 @@ -432,6 +437,7 @@ int ath_startrecv(struct ath_softc *sc)
57 if (list_empty(&sc->rx.rxbuf))
58 goto start_recv;
59
60 + sc->rx.buf_hold = NULL;
61 sc->rx.rxlink = NULL;
62 list_for_each_entry_safe(bf, tbf, &sc->rx.rxbuf, list) {
63 ath_rx_buf_link(sc, bf);
64 @@ -677,6 +683,9 @@ static struct ath_buf *ath_get_next_rx_b
65 }
66
67 bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
68 + if (bf == sc->rx.buf_hold)
69 + return NULL;
70 +
71 ds = bf->bf_desc;
72
73 /*
74 @@ -1391,7 +1400,7 @@ requeue:
75 if (edma) {
76 ath_rx_edma_buf_link(sc, qtype);
77 } else {
78 - ath_rx_buf_link(sc, bf);
79 + ath_rx_buf_relink(sc, bf);
80 ath9k_hw_rxena(ah);
81 }
82 } while (1);