diff options
| author | Luis R. Rodriguez <lrodriguez@atheros.com> | 2008-11-20 17:15:13 -0800 |
|---|---|---|
| committer | John W. Linville <linville@tuxdriver.com> | 2008-11-25 16:13:08 -0500 |
| commit | b4b6cda2298b0c9a0af902312184b775b8867c65 (patch) | |
| tree | 7357a39a07d5cb7a4360161fb8acaa09a198c77d /drivers/net | |
| parent | ca0c7e5101fd4f37fed8e851709f08580b92fbb3 (diff) | |
ath9k: correct expected max RX buffer size
We should only tell the hardware its capable of DMA'ing
to us only what we asked dev_alloc_skb(). Prior to this
it is possible a large RX'd frame could have corrupted
DMA data but for us but we were saved only because we
were previously also pci_map_single()'ing the same large
value. The issue prior to this though was we were unmapping
a smaller amount which the prior DMA patch fixed.
Signed-off-by: Bennyam Malavazi <Bennyam.Malavazi@atheros.com>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'drivers/net')
| -rw-r--r-- | drivers/net/wireless/ath9k/recv.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/drivers/net/wireless/ath9k/recv.c b/drivers/net/wireless/ath9k/recv.c index ad5f88879dc4..504a0444d89f 100644 --- a/drivers/net/wireless/ath9k/recv.c +++ b/drivers/net/wireless/ath9k/recv.c @@ -49,10 +49,12 @@ static void ath_rx_buf_link(struct ath_softc *sc, struct ath_buf *bf) ASSERT(skb != NULL); ds->ds_vdata = skb->data; - /* setup rx descriptors */ + /* setup rx descriptors. The sc_rxbufsize here tells the harware + * how much data it can DMA to us and that we are prepared + * to process */ ath9k_hw_setuprxdesc(ah, ds, - skb_tailroom(skb), /* buffer size */ + sc->sc_rxbufsize, 0); if (sc->sc_rxlink == NULL) @@ -398,6 +400,13 @@ static struct sk_buff *ath_rxbuf_alloc(struct ath_softc *sc, * in rx'd frames. */ + /* Note: the kernel can allocate a value greater than + * what we ask it to give us. We really only need 4 KB as that + * is this hardware supports and in fact we need at least 3849 + * as that is the MAX AMSDU size this hardware supports. + * Unfortunately this means we may get 8 KB here from the + * kernel... and that is actually what is observed on some + * systems :( */ skb = dev_alloc_skb(len + sc->sc_cachelsz - 1); if (skb != NULL) { off = ((unsigned long) skb->data) % sc->sc_cachelsz; |