libertas: Fix problem with broken V4 firmware on CF8381

Firmware V4 on CF8381 reports region code shifted by 1 byte to left.
The following patch checks for this and handles it properly.
Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/libertas/cmd.c

@@ -135,7 +135,13 @@ int lbs_update_hw_spec(struct lbs_private *priv)
 	/* Clamp region code to 8-bit since FW spec indicates that it should
 	 * only ever be 8-bit, even though the field size is 16-bit.  Some firmware
 	 * returns non-zero high 8 bits here.
+	 *
+	 * Firmware version 4.0.102 used in CF8381 has region code shifted.  We
+	 * need to check for this problem and handle it properly.
 	 */
+	if (MRVL_FW_MAJOR_REV(priv->fwrelease) == MRVL_FW_V4)
+		priv->regioncode = (le16_to_cpu(cmd.regioncode) >> 8) & 0xFF;
+	else
 		priv->regioncode = le16_to_cpu(cmd.regioncode) & 0xFF;
 
 	for (i = 0; i < MRVDRV_MAX_REGION_CODE; i++) {

drivers/net/wireless/libertas/defs.h

@@ -234,6 +234,8 @@ static inline void lbs_deb_hex(unsigned int grp, const char *prompt, u8 *buf, in
 /** Mesh enable bit in FW capability */
 #define MESH_CAPINFO_ENABLE_MASK			(1<<16)
 
+/** FW definition from Marvell v4 */
+#define MRVL_FW_V4					(0x04)
 /** FW definition from Marvell v5 */
 #define MRVL_FW_V5					(0x05)
 /** FW definition from Marvell v10 */