rt2x00: Fix failed SLEEP->AWAKE and AWAKE->SLEEP transitions.

(Based on a patch created by Ondrej Zary)

In some circumstances the Ralink devices do not properly go to sleep
or wake up, with timeouts occurring.
Fix this by retrying telling the device that it has to wake up or
sleep.

Signed-off-by: Gertjan van Wingerde <gwingerde@gmail.com>
Acked-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rt2x00/rt2400pci.c b/drivers/net/wireless/rt2x00/rt2400pci.c
index 4ba7b038..ad2c98a 100644
--- a/drivers/net/wireless/rt2x00/rt2400pci.c
+++ b/drivers/net/wireless/rt2x00/rt2400pci.c
@@ -926,7 +926,7 @@
 static int rt2400pci_set_state(struct rt2x00_dev *rt2x00dev,
 			       enum dev_state state)
 {
-	u32 reg;
+	u32 reg, reg2;
 	unsigned int i;
 	char put_to_sleep;
 	char bbp_state;
@@ -947,11 +947,12 @@
 	 * device has entered the correct state.
 	 */
 	for (i = 0; i < REGISTER_BUSY_COUNT; i++) {
-		rt2x00pci_register_read(rt2x00dev, PWRCSR1, &reg);
-		bbp_state = rt2x00_get_field32(reg, PWRCSR1_BBP_CURR_STATE);
-		rf_state = rt2x00_get_field32(reg, PWRCSR1_RF_CURR_STATE);
+		rt2x00pci_register_read(rt2x00dev, PWRCSR1, &reg2);
+		bbp_state = rt2x00_get_field32(reg2, PWRCSR1_BBP_CURR_STATE);
+		rf_state = rt2x00_get_field32(reg2, PWRCSR1_RF_CURR_STATE);
 		if (bbp_state == state && rf_state == state)
 			return 0;
+		rt2x00pci_register_write(rt2x00dev, PWRCSR1, reg);
 		msleep(10);
 	}