wl1251: fix channel switching in monitor mode

Use the ENABLE_RX command for channel switching when no interface is present
(monitor mode only).
The advantage of ENABLE_RX is that it leaves the tx data path disabled in
firmware, whereas the usual JOIN command seems to transmit some frames at
firmware level.

Signed-off-by: David Gnedt <david.gnedt@davizone.at>
Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/ti/wl1251/main.c b/drivers/net/wireless/ti/wl1251/main.c
index c77c456..855026a 100644 (file)
--- a/drivers/net/wireless/ti/wl1251/main.c
+++ b/drivers/net/wireless/ti/wl1251/main.c
@@ -615,8 +615,19 @@ static int wl1251_op_config(struct ieee80211_hw *hw, u32 changed)
        if (channel != wl->channel) {
                wl->channel = channel;
 
-               ret = wl1251_join(wl, wl->bss_type, wl->channel,
-                                 wl->beacon_int, wl->dtim_period);
+               /*
+                * Use ENABLE_RX command for channel switching when no
+                * interface is present (monitor mode only).
+                * This leaves the tx path disabled in firmware, whereas
+                * the usual JOIN command seems to transmit some frames
+                * at firmware level.
+                */
+               if (wl->vif == NULL) {
+                       ret = wl1251_cmd_data_path_rx(wl, wl->channel, 1);
+               } else {
+                       ret = wl1251_join(wl, wl->bss_type, wl->channel,
+                                         wl->beacon_int, wl->dtim_period);
+               }
                if (ret < 0)
                        goto out_sleep;
        }