1 files changed, 27 insertions, 8 deletions

diff --git a/drivers/usb/serial/mos7840.c b/drivers/usb/serial/mos7840.c
index a0d5ea545982..7e998081e1cd 100644
--- a/drivers/usb/serial/mos7840.c
+++ b/drivers/usb/serial/mos7840.c
@@ -2142,13 +2142,21 @@ static int mos7840_ioctl(struct tty_struct *tty,
 static int mos7810_check(struct usb_serial *serial)
 {
         int i, pass_count = 0;
+        u8 *buf;
         __u16 data = 0, mcr_data = 0;
         __u16 test_pattern = 0x55AA;
+        int res;
+
+        buf = kmalloc(VENDOR_READ_LENGTH, GFP_KERNEL);
+        if (!buf)
+                return 0;       /* failed to identify 7810 */
 
         /* Store MCR setting */
-        usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
+        res = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
                 MCS_RDREQ, MCS_RD_RTYPE, 0x0300, MODEM_CONTROL_REGISTER,
-                &mcr_data, VENDOR_READ_LENGTH, MOS_WDR_TIMEOUT);
+                buf, VENDOR_READ_LENGTH, MOS_WDR_TIMEOUT);
+        if (res == VENDOR_READ_LENGTH)
+                mcr_data = *buf;
 
         for (i = 0; i < 16; i++) {
                 /* Send the 1-bit test pattern out to MCS7810 test pin */
@@ -2158,9 +2166,12 @@ static int mos7810_check(struct usb_serial *serial)
                         MODEM_CONTROL_REGISTER, NULL, 0, MOS_WDR_TIMEOUT);
 
                 /* Read the test pattern back */
-                usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
-                        MCS_RDREQ, MCS_RD_RTYPE, 0, GPIO_REGISTER, &data,
-                        VENDOR_READ_LENGTH, MOS_WDR_TIMEOUT);
+                res = usb_control_msg(serial->dev,
+                                usb_rcvctrlpipe(serial->dev, 0), MCS_RDREQ,
+                                MCS_RD_RTYPE, 0, GPIO_REGISTER, buf,
+                                VENDOR_READ_LENGTH, MOS_WDR_TIMEOUT);
+                if (res == VENDOR_READ_LENGTH)
+                        data = *buf;
 
                 /* If this is a MCS7810 device, both test patterns must match */
                 if (((test_pattern >> i) ^ (~data >> 1)) & 0x0001)
@@ -2174,6 +2185,8 @@ static int mos7810_check(struct usb_serial *serial)
                 MCS_WR_RTYPE, 0x0300 | mcr_data, MODEM_CONTROL_REGISTER, NULL,
                 0, MOS_WDR_TIMEOUT);
 
+        kfree(buf);
+
         if (pass_count == 16)
                 return 1;
 
@@ -2183,11 +2196,17 @@ static int mos7810_check(struct usb_serial *serial)
 static int mos7840_calc_num_ports(struct usb_serial *serial)
 {
         __u16 data = 0x00;
+        u8 *buf;
         int mos7840_num_ports;
 
-        usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
-                MCS_RDREQ, MCS_RD_RTYPE, 0, GPIO_REGISTER, &data,
-                VENDOR_READ_LENGTH, MOS_WDR_TIMEOUT);
+        buf = kzalloc(VENDOR_READ_LENGTH, GFP_KERNEL);
+        if (buf) {
+                usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
+                        MCS_RDREQ, MCS_RD_RTYPE, 0, GPIO_REGISTER, buf,
+                        VENDOR_READ_LENGTH, MOS_WDR_TIMEOUT);
+                data = *buf;
+                kfree(buf);
+        }
 
         if (serial->dev->descriptor.idProduct == MOSCHIP_DEVICE_ID_7810 ||
                 serial->dev->descriptor.idProduct == MOSCHIP_DEVICE_ID_7820) {