diff options
Diffstat (limited to 'drivers/net/wireless/at76c50x-usb.c')
| -rw-r--r-- | drivers/net/wireless/at76c50x-usb.c | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/drivers/net/wireless/at76c50x-usb.c b/drivers/net/wireless/at76c50x-usb.c index 10fd12ec85be..d48776e4f343 100644 --- a/drivers/net/wireless/at76c50x-usb.c +++ b/drivers/net/wireless/at76c50x-usb.c @@ -1429,6 +1429,8 @@ static int at76_startup_device(struct at76_priv *priv) /* remove BSSID from previous run */ memset(priv->bssid, 0, ETH_ALEN); + priv->scanning = false; + if (at76_set_radio(priv, 1) == 1) at76_wait_completion(priv, CMD_RADIO_ON); @@ -1502,6 +1504,52 @@ static void at76_work_submit_rx(struct work_struct *work) mutex_unlock(&priv->mtx); } +/* This is a workaround to make scan working: + * currently mac80211 does not process frames with no frequency + * information. + * However during scan the HW performs a sweep by itself, and we + * are unable to know where the radio is actually tuned. + * This function tries to do its best to guess this information.. + * During scan, If the current frame is a beacon or a probe response, + * the channel information is extracted from it. + * When not scanning, for other frames, or if it happens that for + * whatever reason we fail to parse beacons and probe responses, this + * function returns the priv->channel information, that should be correct + * at least when we are not scanning. + */ +static inline int at76_guess_freq(struct at76_priv *priv) +{ + size_t el_off; + const u8 *el; + int channel = priv->channel; + int len = priv->rx_skb->len; + struct ieee80211_hdr *hdr = (void *)priv->rx_skb->data; + + if (!priv->scanning) + goto exit; + + if (len < 24) + goto exit; + + if (ieee80211_is_probe_resp(hdr->frame_control)) { + el_off = offsetof(struct ieee80211_mgmt, u.probe_resp.variable); + el = ((struct ieee80211_mgmt *)hdr)->u.probe_resp.variable; + } else if (ieee80211_is_beacon(hdr->frame_control)) { + el_off = offsetof(struct ieee80211_mgmt, u.beacon.variable); + el = ((struct ieee80211_mgmt *)hdr)->u.beacon.variable; + } else { + goto exit; + } + len -= el_off; + + el = cfg80211_find_ie(WLAN_EID_DS_PARAMS, el, len); + if (el && el[1] > 0) + channel = el[2]; + +exit: + return ieee80211_channel_to_frequency(channel, IEEE80211_BAND_2GHZ); +} + static void at76_rx_tasklet(unsigned long param) { struct urb *urb = (struct urb *)param; @@ -1542,6 +1590,8 @@ static void at76_rx_tasklet(unsigned long param) rx_status.signal = buf->rssi; rx_status.flag |= RX_FLAG_DECRYPTED; rx_status.flag |= RX_FLAG_IV_STRIPPED; + rx_status.band = IEEE80211_BAND_2GHZ; + rx_status.freq = at76_guess_freq(priv); at76_dbg(DBG_MAC80211, "calling ieee80211_rx_irqsafe(): %d/%d", priv->rx_skb->len, priv->rx_skb->data_len); @@ -1894,6 +1944,8 @@ static void at76_dwork_hw_scan(struct work_struct *work) if (is_valid_ether_addr(priv->bssid)) at76_join(priv); + priv->scanning = false; + mutex_unlock(&priv->mtx); ieee80211_scan_completed(priv->hw, false); @@ -1948,6 +2000,7 @@ static int at76_hw_scan(struct ieee80211_hw *hw, goto exit; } + priv->scanning = true; ieee80211_queue_delayed_work(priv->hw, &priv->dwork_hw_scan, SCAN_POLL_INTERVAL); |