mwl8k: properly set receive status rate index on 5 GHz receive

The mwl8k firmware uses indices into the 2.4 GHz band rate table for
the receive descriptor channel field even if the packet was received
on a 5 GHz channel, while mac80211 expects an index into the 5 GHz
band rate table when packets are received on the 5 GHz band, which
presents a mismatch as the 5 GHz band rate table lacks the five
non-OFDM rates that the 2.4 GHz rate table starts with.

To handle this properly, we need to substract 5 from the rate index
field if the packet was received on a 5 GHz channel (and was not
received at an MCS rate).

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/mwl8k.c

@@ -759,7 +759,13 @@ mwl8k_rxd_8366_ap_process(void *_rxd, struct ieee80211_rx_status *status,
 		}
 	}
 
-	status->band = IEEE80211_BAND_2GHZ;
+	if (rxd->channel > 14) {
+		status->band = IEEE80211_BAND_5GHZ;
+		if (!(status->flag & RX_FLAG_HT))
+			status->rate_idx -= 5;
+	} else {
+		status->band = IEEE80211_BAND_2GHZ;
+	}
 	status->freq = ieee80211_channel_to_frequency(rxd->channel);
 
 	*qos = rxd->qos_control;
@@ -850,7 +856,13 @@ mwl8k_rxd_sta_process(void *_rxd, struct ieee80211_rx_status *status,
 	if (rate_info & MWL8K_STA_RATE_INFO_MCS_FORMAT)
 		status->flag |= RX_FLAG_HT;
 
-	status->band = IEEE80211_BAND_2GHZ;
+	if (rxd->channel > 14) {
+		status->band = IEEE80211_BAND_5GHZ;
+		if (!(status->flag & RX_FLAG_HT))
+			status->rate_idx -= 5;
+	} else {
+		status->band = IEEE80211_BAND_2GHZ;
+	}
 	status->freq = ieee80211_channel_to_frequency(rxd->channel);
 
 	*qos = rxd->qos_control;