commit 99ade2597e3f7f0ad463c489aaccd6cc605e242c
author Ivo van Doorn <ivdoorn@gmail.com> Fri Jun 20 22:11:00 2008 +0200
committer John W. Linville <linville@tuxdriver.com> Wed Jun 25 10:56:16 2008 -0400
tree a644c9c689cded6ebdb46953180af82d7d3fcdd4
parent 2f9ec47d0954f9d2e5a00209c2689cbc477a8c89

rt2x00: Fix unbalanced mutex locking

The usb_cache_mutex was not correctly released
under all circumstances. Both rt73usb as rt2500usb
didn't release the mutex under certain conditions
when the register access failed. Obviously such
failure would lead to deadlocks.

In addition under similar circumstances when the
bbp register couldn't be read the value must be
set to 0xff to indicate that the value is wrong.
This too didn't happen under all circumstances.

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

drivers/net/wireless/rt2x00/rt2500usb.c

diff --git a/drivers/net/wireless/rt2x00/rt2500usb.c b/drivers/net/wireless/rt2x00/rt2500usb.c
index fdbd0ef..61e59c1 100644
--- a/drivers/net/wireless/rt2x00/rt2500usb.c
+++ b/drivers/net/wireless/rt2x00/rt2500usb.c
@@ -138,11 +138,8 @@
 	 * Wait until the BBP becomes ready.
 	 */
 	reg = rt2500usb_bbp_check(rt2x00dev);
-	if (rt2x00_get_field16(reg, PHY_CSR8_BUSY)) {
-		ERROR(rt2x00dev, "PHY_CSR8 register busy. Write failed.\n");
-		mutex_unlock(&rt2x00dev->usb_cache_mutex);
-		return;
-	}
+	if (rt2x00_get_field16(reg, PHY_CSR8_BUSY))
+		goto exit_fail;
 
 	/*
 	 * Write the data into the BBP.
@@ -155,6 +152,13 @@
 	rt2500usb_register_write_lock(rt2x00dev, PHY_CSR7, reg);
 
 	mutex_unlock(&rt2x00dev->usb_cache_mutex);
+
+	return;
+
+exit_fail:
+	mutex_unlock(&rt2x00dev->usb_cache_mutex);
+
+	ERROR(rt2x00dev, "PHY_CSR8 register busy. Write failed.\n");
 }
 
 static void rt2500usb_bbp_read(struct rt2x00_dev *rt2x00dev,
@@ -168,10 +172,8 @@
 	 * Wait until the BBP becomes ready.
 	 */
 	reg = rt2500usb_bbp_check(rt2x00dev);
-	if (rt2x00_get_field16(reg, PHY_CSR8_BUSY)) {
-		ERROR(rt2x00dev, "PHY_CSR8 register busy. Read failed.\n");
-		return;
-	}
+	if (rt2x00_get_field16(reg, PHY_CSR8_BUSY))
+		goto exit_fail;
 
 	/*
 	 * Write the request into the BBP.
@@ -186,17 +188,21 @@
 	 * Wait until the BBP becomes ready.
 	 */
 	reg = rt2500usb_bbp_check(rt2x00dev);
-	if (rt2x00_get_field16(reg, PHY_CSR8_BUSY)) {
-		ERROR(rt2x00dev, "PHY_CSR8 register busy. Read failed.\n");
-		*value = 0xff;
-		mutex_unlock(&rt2x00dev->usb_cache_mutex);
-		return;
-	}
+	if (rt2x00_get_field16(reg, PHY_CSR8_BUSY))
+		goto exit_fail;
 
 	rt2500usb_register_read_lock(rt2x00dev, PHY_CSR7, &reg);
 	*value = rt2x00_get_field16(reg, PHY_CSR7_DATA);
 
 	mutex_unlock(&rt2x00dev->usb_cache_mutex);
+
+	return;
+
+exit_fail:
+	mutex_unlock(&rt2x00dev->usb_cache_mutex);
+
+	ERROR(rt2x00dev, "PHY_CSR8 register busy. Read failed.\n");
+	*value = 0xff;
 }
 
 static void rt2500usb_rf_write(struct rt2x00_dev *rt2x00dev,