[PATCH] revert incorrect mutex conversion in hdaps driver

This reverts the mutex conversion that was recently done to the hdaps
driver; this coversion was buggy because the hdaps driver started using
this semaphore in IRQ context, which mutexes do not allow.  Easiest
solution for now is to just revert the patch (the patch was part of a
bigger GIT commit, 9a61bf6300533d3b64d7ff29adfec00e596de67d but this
only reverts this one file)

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/hwmon/hdaps.c

@@ -33,7 +33,6 @@
 #include <linux/module.h>
 #include <linux/timer.h>
 #include <linux/dmi.h>
-#include <linux/mutex.h>
 #include <asm/io.h>
 
 #define HDAPS_LOW_PORT		0x1600	/* first port used by hdaps */
@@ -71,10 +70,10 @@ static u8 km_activity;
 static int rest_x;
 static int rest_y;
 
-static DEFINE_MUTEX(hdaps_mutex);
+static DECLARE_MUTEX(hdaps_sem);
 
 /*
- * __get_latch - Get the value from a given port.  Callers must hold hdaps_mutex.
+ * __get_latch - Get the value from a given port.  Callers must hold hdaps_sem.
  */
 static inline u8 __get_latch(u16 port)
 {
@@ -83,7 +82,7 @@ static inline u8 __get_latch(u16 port)
 
 /*
  * __check_latch - Check a port latch for a given value.  Returns zero if the
- * port contains the given value.  Callers must hold hdaps_mutex.
+ * port contains the given value.  Callers must hold hdaps_sem.
  */
 static inline int __check_latch(u16 port, u8 val)
 {
@@ -94,7 +93,7 @@ static inline int __check_latch(u16 port, u8 val)
 
 /*
  * __wait_latch - Wait up to 100us for a port latch to get a certain value,
- * returning zero if the value is obtained.  Callers must hold hdaps_mutex.
+ * returning zero if the value is obtained.  Callers must hold hdaps_sem.
  */
 static int __wait_latch(u16 port, u8 val)
 {
@@ -111,7 +110,7 @@ static int __wait_latch(u16 port, u8 val)
 
 /*
  * __device_refresh - request a refresh from the accelerometer.  Does not wait
- * for refresh to complete.  Callers must hold hdaps_mutex.
+ * for refresh to complete.  Callers must hold hdaps_sem.
  */
 static void __device_refresh(void)
 {
@@ -125,7 +124,7 @@ static void __device_refresh(void)
 /*
  * __device_refresh_sync - request a synchronous refresh from the
  * accelerometer.  We wait for the refresh to complete.  Returns zero if
- * successful and nonzero on error.  Callers must hold hdaps_mutex.
+ * successful and nonzero on error.  Callers must hold hdaps_sem.
  */
 static int __device_refresh_sync(void)
 {
@@ -135,7 +134,7 @@ static int __device_refresh_sync(void)
 
 /*
  * __device_complete - indicate to the accelerometer that we are done reading
- * data, and then initiate an async refresh.  Callers must hold hdaps_mutex.
+ * data, and then initiate an async refresh.  Callers must hold hdaps_sem.
  */
 static inline void __device_complete(void)
 {
@@ -153,7 +152,7 @@ static int hdaps_readb_one(unsigned int port, u8 *val)
 {
 	int ret;
 
-	mutex_lock(&hdaps_mutex);
+	down(&hdaps_sem);
 
 	/* do a sync refresh -- we need to be sure that we read fresh data */
 	ret = __device_refresh_sync();
@@ -164,7 +163,7 @@ static int hdaps_readb_one(unsigned int port, u8 *val)
 	__device_complete();
 
 out:
-	mutex_unlock(&hdaps_mutex);
+	up(&hdaps_sem);
 	return ret;
 }
 
@@ -199,9 +198,9 @@ static int hdaps_read_pair(unsigned int port1, unsigned int port2,
 {
 	int ret;
 
-	mutex_lock(&hdaps_mutex);
+	down(&hdaps_sem);
 	ret = __hdaps_read_pair(port1, port2, val1, val2);
-	mutex_unlock(&hdaps_mutex);
+	up(&hdaps_sem);
 
 	return ret;
 }
@@ -214,7 +213,7 @@ static int hdaps_device_init(void)
 {
 	int total, ret = -ENXIO;
 
-	mutex_lock(&hdaps_mutex);
+	down(&hdaps_sem);
 
 	outb(0x13, 0x1610);
 	outb(0x01, 0x161f);
@@ -280,7 +279,7 @@ static int hdaps_device_init(void)
 	}
 
 out:
-	mutex_unlock(&hdaps_mutex);
+	up(&hdaps_sem);
 	return ret;
 }
 
@@ -314,7 +313,7 @@ static struct platform_driver hdaps_driver = {
 };
 
 /*
- * hdaps_calibrate - Set our "resting" values.  Callers must hold hdaps_mutex.
+ * hdaps_calibrate - Set our "resting" values.  Callers must hold hdaps_sem.
  */
 static void hdaps_calibrate(void)
 {
@@ -326,7 +325,7 @@ static void hdaps_mousedev_poll(unsigned long unused)
 	int x, y;
 
 	/* Cannot sleep.  Try nonblockingly.  If we fail, try again later. */
-	if (!mutex_trylock(&hdaps_mutex)) {
+	if (down_trylock(&hdaps_sem)) {
 		mod_timer(&hdaps_timer,jiffies + HDAPS_POLL_PERIOD);
 		return;
 	}
@@ -341,7 +340,7 @@ static void hdaps_mousedev_poll(unsigned long unused)
 	mod_timer(&hdaps_timer, jiffies + HDAPS_POLL_PERIOD);
 
 out:
-	mutex_unlock(&hdaps_mutex);
+	up(&hdaps_sem);
 }
 
 
@@ -421,9 +420,9 @@ static ssize_t hdaps_calibrate_store(struct device *dev,
 				     struct device_attribute *attr,
 				     const char *buf, size_t count)
 {
-	mutex_lock(&hdaps_mutex);
+	down(&hdaps_sem);
 	hdaps_calibrate();
-	mutex_unlock(&hdaps_mutex);
+	up(&hdaps_sem);
 
 	return count;
 }