[PATCH v2 3/6] USB: serial: f81232: use usb_control_msg_recv() and usb_control_msg_send()

[Himadri Pandya <himadrispandya@xxxxxxxxx>]

New wrapper functions usb_control_msg_send/recv accept stack variables
for usb message buffer and eliminate the need of creating temporary dma
buffers. The wrappers also have proper error checks for short
read/writes. Hence use the wrappers instead of using usb_control_msg()
directly.

Signed-off-by: Himadri Pandya <himadrispandya@xxxxxxxxx>
---
Changes in v2:
 - Drop unrelated style changes
---
 drivers/usb/serial/f81232.c | 96 +++++++++++++------------------------
 1 file changed, 34 insertions(+), 62 deletions(-)

diff --git a/drivers/usb/serial/f81232.c b/drivers/usb/serial/f81232.c
index a7a7af8d05bf..3ad1f515fb68 100644
--- a/drivers/usb/serial/f81232.c
+++ b/drivers/usb/serial/f81232.c
@@ -139,67 +139,46 @@ static int calc_baud_divisor(speed_t baudrate, speed_t clockrate)
 static int f81232_get_register(struct usb_serial_port *port, u16 reg, u8 *val)
 {
 	int status;
-	u8 *tmp;
 	struct usb_device *dev = port->serial->dev;
 
-	tmp = kmalloc(sizeof(*val), GFP_KERNEL);
-	if (!tmp)
-		return -ENOMEM;
-
-	status = usb_control_msg(dev,
-				usb_rcvctrlpipe(dev, 0),
-				F81232_REGISTER_REQUEST,
-				F81232_GET_REGISTER,
-				reg,
-				0,
-				tmp,
-				sizeof(*val),
-				USB_CTRL_GET_TIMEOUT);
-	if (status != sizeof(*val)) {
+	status = usb_control_msg_recv(dev,
+				      0,
+				      F81232_REGISTER_REQUEST,
+				      F81232_GET_REGISTER,
+				      reg,
+				      0,
+				      val,
+				      sizeof(*val),
+				      USB_CTRL_GET_TIMEOUT,
+				      GFP_KERNEL);
+	if (status) {
 		dev_err(&port->dev, "%s failed status: %d\n", __func__, status);
-
-		if (status < 0)
-			status = usb_translate_errors(status);
-		else
-			status = -EIO;
-	} else {
-		status = 0;
-		*val = *tmp;
+		status = usb_translate_errors(status);
 	}
 
-	kfree(tmp);
 	return status;
 }
 
 static int f81232_set_register(struct usb_serial_port *port, u16 reg, u8 val)
 {
 	int status;
-	u8 *tmp;
 	struct usb_device *dev = port->serial->dev;
 
-	tmp = kmalloc(sizeof(val), GFP_KERNEL);
-	if (!tmp)
-		return -ENOMEM;
-
-	*tmp = val;
-
-	status = usb_control_msg(dev,
-				usb_sndctrlpipe(dev, 0),
-				F81232_REGISTER_REQUEST,
-				F81232_SET_REGISTER,
-				reg,
-				0,
-				tmp,
-				sizeof(val),
-				USB_CTRL_SET_TIMEOUT);
-	if (status < 0) {
+	status = usb_control_msg_send(dev,
+				      0,
+				      F81232_REGISTER_REQUEST,
+				      F81232_SET_REGISTER,
+				      reg,
+				      0,
+				      &val,
+				      sizeof(val),
+				      USB_CTRL_SET_TIMEOUT,
+				      GFP_KERNEL);
+	if (status) {
 		dev_err(&port->dev, "%s failed status: %d\n", __func__, status);
 		status = usb_translate_errors(status);
-	} else {
-		status = 0;
 	}
 
-	kfree(tmp);
 	return status;
 }
 
@@ -857,28 +836,22 @@ static int f81534a_ctrl_set_register(struct usb_interface *intf, u16 reg,
 	struct usb_device *dev = interface_to_usbdev(intf);
 	int retry = F81534A_ACCESS_REG_RETRY;
 	int status;
-	u8 *tmp;
-
-	tmp = kmemdup(val, size, GFP_KERNEL);
-	if (!tmp)
-		return -ENOMEM;
 
 	while (retry--) {
-		status = usb_control_msg(dev,
-					usb_sndctrlpipe(dev, 0),
-					F81232_REGISTER_REQUEST,
-					F81232_SET_REGISTER,
-					reg,
-					0,
-					tmp,
-					size,
-					USB_CTRL_SET_TIMEOUT);
-		if (status < 0) {
+		status = usb_control_msg_send(dev,
+					      0,
+					      F81232_REGISTER_REQUEST,
+					      F81232_SET_REGISTER,
+					      reg,
+					      0,
+					      val,
+					      size,
+					      USB_CTRL_SET_TIMEOUT,
+					      GFP_KERNEL);
+		if (status) {
 			status = usb_translate_errors(status);
 			if (status == -EIO)
 				continue;
-		} else {
-			status = 0;
 		}
 
 		break;
@@ -889,7 +862,6 @@ static int f81534a_ctrl_set_register(struct usb_interface *intf, u16 reg,
 				reg, status);
 	}
 
-	kfree(tmp);
 	return status;
 }
 
-- 
2.17.1