wlcore: change the wait for event mechanism

wlcore needs to wait for certain events for example
for roc complete event. Usually the events are received
from the FW very fast, therefore wlcore can poll with
a short delay and if after a second the event was
not received yet poll with a long (1-5 msec) delay.

This implementation is similar to the sending of
commands to the FW.

Empirically the change reduced the wait for roc event
from ~10-40msec to 100s of usecs.

[replace udelay/msleep with usleep_range - Arik]
Signed-off-by: Yoni Divinsky <yoni.divinsky@ti.com>
Signed-off-by: Arik Nemtsov <arik@wizery.com>

drivers/net/wireless/ti/wlcore/cmd.c

@@ -39,6 +39,7 @@
 #include "hw_ops.h"
 
 #define WL1271_CMD_FAST_POLL_COUNT       50
+#define WL1271_WAIT_EVENT_FAST_POLL_COUNT 20
 
 /*
  * send command to firmware
@@ -138,6 +139,7 @@ static int wl1271_cmd_wait_for_event_or_timeout(struct wl1271 *wl,
 	u32 *events_vector;
 	u32 event;
 	unsigned long timeout_time;
+	u16 poll_count = 0;
 	int ret = 0;
 
 	*timeout = false;
@@ -156,7 +158,11 @@ static int wl1271_cmd_wait_for_event_or_timeout(struct wl1271 *wl,
 			goto out;
 		}
 
-		msleep(1);
+		poll_count++;
+		if (poll_count < WL1271_WAIT_EVENT_FAST_POLL_COUNT)
+			usleep_range(50, 51);
+		else
+			usleep_range(1000, 5000);
 
 		/* read from both event fields */
 		ret = wlcore_read(wl, wl->mbox_ptr[0], events_vector,