[PATCH 3.13 048/140] ath9k: Use correct channel for RX packets

Greg Kroah-Hartman
2014-02-04T21:45:18Z

From: Sujith Manoharan <c_manoha@qca.qualcomm.com>

commit ff9a93f2ebb88ac7aab9568de80b64b92078e96d upstream.

Accessing the current channel definition in mac80211
when processing RX packets is problematic because it
could have been updated when a scan is issued. Since a
channel change involves flushing the existing packets
in the RX queue before a chip-reset is done, they would
be processed using the wrong band/channel information.

To avoid this, use the current channel information
maintained in the driver.

Reported-by: Oleksij Rempel <linux@rempel-privat.de>
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/net/wireless/ath/ath9k/recv.c | 25 ++++++++++++++-----------
1 file changed, 14 insertions(+), 11 deletions(-)

--- a/drivers/net/wireless/ath/ath9k/recv.c
+++ b/drivers/net/wireless/ath/ath9k/recv.c
@@ -851,20 +851,15 @@ static int ath9k_process_rate(struct ath
enum ieee80211_band band;
unsigned int i = 0;
struct ath_softc __maybe_unused *sc = common->priv;
+ struct ath_hw *ah = sc->sc_ah;

- band = hw->conf.chandef.chan->band;
+ band = ah->curchan->chan->band;
sband = hw->wiphy->bands[band];

- switch (hw->conf.chandef.width) {
- case NL80211_CHAN_WIDTH_5:
+ if (IS_CHAN_QUARTER_RATE(ah->curchan))
rxs->flag |= RX_FLAG_5MHZ;
- break;
- case NL80211_CHAN_WIDTH_10:
+ else if (IS_CHAN_HALF_RATE(ah->curchan))
rxs->flag |= RX_FLAG_10MHZ;
- break;
- default:
- break;
- }

if (rx_stats->rs_rate & 0x80) {
/* HT rate */
@@ -1248,6 +1243,14 @@ static int ath9k_rx_skb_preprocess(struc
ath_start_rx_poll(sc, 3);
}

+ /*
+ * This shouldn't happen, but have a safety check anyway.
+ */
+ if (WARN_ON(!ah->curchan)) {
+ ret = -EINVAL;
+ goto exit;
+ }
+
if (ath9k_process_rate(common, hw, rx_stats, rx_status)) {
ret =-EINVAL;
goto exit;
@@ -1255,8 +1258,8 @@ static int ath9k_rx_skb_preprocess(struc

ath9k_process_rssi(common, hw, rx_stats, rx_status);

- rx_status->band = hw->conf.chandef.chan->band;
- rx_status->freq = hw->conf.chandef.chan->center_freq;
+ rx_status->band = ah->curchan->chan->band;
+ rx_status->freq = ah->curchan->chan->center_freq;
rx_status->antenna = rx_stats->rs_antenna;
rx_status->flag |= RX_FLAG_MACTIME_END;