rt2x00: Fix BUG on rt2800usb when trying to read eFuse EEPROM.

Current tree hits a BUG_ON in rt2x00_regbusy_read, because the eFuse EEPROM
reading code of rt2800lib uses the function without the csr_mutex locked.

Fix this by locking the csr_mutex for the of the EEPROM reading cycly and
using the _lock variants of the register reading and writing functions.

This also introcudes the register_read_lock function pointer in the
rt2800_ops structure.

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>

1 files changed, 14 insertions, 10 deletions

diff --git a/drivers/net/wireless/rt2x00/rt2800lib.c b/drivers/net/wireless/rt2x00/rt2800lib.c
index c7108050af3..621dac18ca6 100644
--- a/drivers/net/wireless/rt2x00/rt2800lib.c
+++ b/drivers/net/wireless/rt2x00/rt2800lib.c
@@ -1684,24 +1684,28 @@ static void rt2800_efuse_read(struct rt2x00_dev *rt2x00dev, unsigned int i)
 {
         u32 reg;
 
-        rt2800_register_read(rt2x00dev, EFUSE_CTRL, &reg);
+        mutex_lock(&rt2x00dev->csr_mutex);
+
+        rt2800_register_read_lock(rt2x00dev, EFUSE_CTRL, &reg);
         rt2x00_set_field32(&reg, EFUSE_CTRL_ADDRESS_IN, i);
         rt2x00_set_field32(&reg, EFUSE_CTRL_MODE, 0);
         rt2x00_set_field32(&reg, EFUSE_CTRL_KICK, 1);
-        rt2800_register_write(rt2x00dev, EFUSE_CTRL, reg);
+        rt2800_register_write_lock(rt2x00dev, EFUSE_CTRL, reg);
 
         /* Wait until the EEPROM has been loaded */
         rt2800_regbusy_read(rt2x00dev, EFUSE_CTRL, EFUSE_CTRL_KICK, &reg);
 
         /* Apparently the data is read from end to start */
-        rt2800_register_read(rt2x00dev, EFUSE_DATA3,
-                                (u32 *)&rt2x00dev->eeprom[i]);
-        rt2800_register_read(rt2x00dev, EFUSE_DATA2,
-                                (u32 *)&rt2x00dev->eeprom[i + 2]);
-        rt2800_register_read(rt2x00dev, EFUSE_DATA1,
-                                (u32 *)&rt2x00dev->eeprom[i + 4]);
-        rt2800_register_read(rt2x00dev, EFUSE_DATA0,
-                                (u32 *)&rt2x00dev->eeprom[i + 6]);
+        rt2800_register_read_lock(rt2x00dev, EFUSE_DATA3,
+                                        (u32 *)&rt2x00dev->eeprom[i]);
+        rt2800_register_read_lock(rt2x00dev, EFUSE_DATA2,
+                                        (u32 *)&rt2x00dev->eeprom[i + 2]);
+        rt2800_register_read_lock(rt2x00dev, EFUSE_DATA1,
+                                        (u32 *)&rt2x00dev->eeprom[i + 4]);
+        rt2800_register_read_lock(rt2x00dev, EFUSE_DATA0,
+                                        (u32 *)&rt2x00dev->eeprom[i + 6]);
+
+        mutex_unlock(&rt2x00dev->csr_mutex);
 }
 
 void rt2800_read_eeprom_efuse(struct rt2x00_dev *rt2x00dev)