rt2x00: Fix BUG_ON() with antenna handling

With the new configuration handling, and more specifically
splitting the configuration of the antenna from the normal
configuration steps allowed a BUG_ON() to be triggered
in the driver because the SW_DIVERSITY was send to the
driver. This fixes that by catching the value early in
rt2x00config.c and replacing it with a sensible value.

This also fixes a problem where the antenna is not being
initialized at all when the radio is enabled. Since it
no longer is part of the mac80211 configuration the
only place where rt2x00 configured it was the SW diversity
handler. Obviously this is broken for all non-diversity
hardware and breaks SW diversity due to a broken initialization.

When the radio is enabled the antenna will be configured
once as soon as the config() callback function is called.

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 26 insertions, 9 deletions

diff --git a/drivers/net/wireless/rt2x00/rt2x00config.c b/drivers/net/wireless/rt2x00/rt2x00config.c
index 3e4eee3ab7d..1059b4d1868 100644
--- a/drivers/net/wireless/rt2x00/rt2x00config.c
+++ b/drivers/net/wireless/rt2x00/rt2x00config.c
@@ -109,15 +109,32 @@ void rt2x00lib_config_erp(struct rt2x00_dev *rt2x00dev,
 }
 
 void rt2x00lib_config_antenna(struct rt2x00_dev *rt2x00dev,
-                              enum antenna rx, enum antenna tx)
+                              struct antenna_setup *ant)
 {
-        struct antenna_setup ant;
-
-        ant.rx = rx;
-        ant.tx = tx;
+        /*
+         * Failsafe: Make sure we are not sending the
+         * ANTENNA_SW_DIVERSITY state to the driver.
+         * If that happes fallback to hardware default,
+         * or our own default.
+         */
+        if (ant->rx == ANTENNA_SW_DIVERSITY) {
+                if (rt2x00dev->default_ant.rx == ANTENNA_SW_DIVERSITY)
+                        ant->rx = ANTENNA_B;
+                else
+                        ant->rx = rt2x00dev->default_ant.rx;
+        }
+        if (ant->tx == ANTENNA_SW_DIVERSITY) {
+                if (rt2x00dev->default_ant.tx == ANTENNA_SW_DIVERSITY)
+                        ant->tx = ANTENNA_B;
+                else
+                        ant->tx = rt2x00dev->default_ant.tx;
+        }
 
-        if (rx == rt2x00dev->link.ant.active.rx &&
-            tx == rt2x00dev->link.ant.active.tx)
+        /*
+         * Only reconfigure when something has changed.
+         */
+        if (ant->rx == rt2x00dev->link.ant.active.rx &&
+            ant->tx == rt2x00dev->link.ant.active.tx)
                 return;
 
         /*
@@ -132,12 +149,12 @@ void rt2x00lib_config_antenna(struct rt2x00_dev *rt2x00dev,
          * The latter is required since we need to recalibrate the
          * noise-sensitivity ratio for the new setup.
          */
-        rt2x00dev->ops->lib->config_ant(rt2x00dev, &ant);
+        rt2x00dev->ops->lib->config_ant(rt2x00dev, ant);
 
         rt2x00lib_reset_link_tuner(rt2x00dev);
         rt2x00_reset_link_ant_rssi(&rt2x00dev->link);
 
-        memcpy(&rt2x00dev->link.ant.active, &ant, sizeof(ant));
+        memcpy(&rt2x00dev->link.ant.active, ant, sizeof(*ant));
 
         if (test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
                 rt2x00lib_toggle_rx(rt2x00dev, STATE_RADIO_RX_ON_LINK);