[PATCH v2 6/6] USB: serial: kl5kusb105: use usb_control_msg_recv() and usb_control_msg_send()

[Himadri Pandya <himadrispandya@xxxxxxxxx>]

The wrappers usb_control_msg_send/recv eliminate the need of allocating
dma buffers for usb message. They also impose proper error checks on the
return value of usb_control_msg() to handle short read/write. Hence use
the wrappers and remove dma allocations.

Signed-off-by: Himadri Pandya <himadrispandya@xxxxxxxxx>
---
Changes in v2:
 - Fix the caller of klsi_105_chg_port_settings()
 - Drop unnecessary use of the wrappers
---
 drivers/usb/serial/kl5kusb105.c | 79 ++++++++++++++-------------------
 1 file changed, 34 insertions(+), 45 deletions(-)

diff --git a/drivers/usb/serial/kl5kusb105.c b/drivers/usb/serial/kl5kusb105.c
index f1e9628a9907..72d3920c9c48 100644
--- a/drivers/usb/serial/kl5kusb105.c
+++ b/drivers/usb/serial/kl5kusb105.c
@@ -124,16 +124,18 @@ static int klsi_105_chg_port_settings(struct usb_serial_port *port,
 {
 	int rc;
 
-	rc = usb_control_msg(port->serial->dev,
-			usb_sndctrlpipe(port->serial->dev, 0),
-			KL5KUSB105A_SIO_SET_DATA,
-			USB_TYPE_VENDOR | USB_DIR_OUT | USB_RECIP_INTERFACE,
-			0, /* value */
-			0, /* index */
-			settings,
-			sizeof(struct klsi_105_port_settings),
-			KLSI_TIMEOUT);
-	if (rc < 0)
+	rc = usb_control_msg_send(port->serial->dev,
+				  0,
+				  KL5KUSB105A_SIO_SET_DATA,
+				  USB_TYPE_VENDOR | USB_DIR_OUT |
+				  USB_RECIP_INTERFACE,
+				  0, /* value */
+				  0, /* index */
+				  settings,
+				  sizeof(struct klsi_105_port_settings),
+				  KLSI_TIMEOUT,
+				  GFP_KERNEL);
+	if (rc)
 		dev_err(&port->dev,
 			"Change port settings failed (error = %d)\n", rc);
 
@@ -167,28 +169,21 @@ static int klsi_105_get_line_state(struct usb_serial_port *port,
 				   unsigned long *line_state_p)
 {
 	int rc;
-	u8 *status_buf;
+	u8 status_buf[KLSI_STATUSBUF_LEN];
 	__u16 status;
 
-	status_buf = kmalloc(KLSI_STATUSBUF_LEN, GFP_KERNEL);
-	if (!status_buf)
-		return -ENOMEM;
-
 	status_buf[0] = 0xff;
 	status_buf[1] = 0xff;
-	rc = usb_control_msg(port->serial->dev,
-			     usb_rcvctrlpipe(port->serial->dev, 0),
-			     KL5KUSB105A_SIO_POLL,
-			     USB_TYPE_VENDOR | USB_DIR_IN,
-			     0, /* value */
-			     0, /* index */
-			     status_buf, KLSI_STATUSBUF_LEN,
-			     10000
-			     );
-	if (rc != KLSI_STATUSBUF_LEN) {
+	rc = usb_control_msg_recv(port->serial->dev, 0,
+				  KL5KUSB105A_SIO_POLL,
+				  USB_TYPE_VENDOR | USB_DIR_IN,
+				  0, /* value */
+				  0, /* index */
+				  status_buf, KLSI_STATUSBUF_LEN,
+				  10000,
+				  GFP_KERNEL);
+	if (rc) {
 		dev_err(&port->dev, "reading line status failed: %d\n", rc);
-		if (rc >= 0)
-			rc = -EIO;
 	} else {
 		status = get_unaligned_le16(status_buf);
 
@@ -198,7 +193,6 @@ static int klsi_105_get_line_state(struct usb_serial_port *port,
 		*line_state_p = klsi_105_status2linestate(status);
 	}
 
-	kfree(status_buf);
 	return rc;
 }
 
@@ -245,7 +239,7 @@ static int  klsi_105_open(struct tty_struct *tty, struct usb_serial_port *port)
 	int retval = 0;
 	int rc;
 	unsigned long line_state;
-	struct klsi_105_port_settings *cfg;
+	struct klsi_105_port_settings cfg;
 	unsigned long flags;
 
 	/* Do a defined restart:
@@ -255,27 +249,22 @@ static int  klsi_105_open(struct tty_struct *tty, struct usb_serial_port *port)
 	 * Then read the modem line control and store values in
 	 * priv->line_state.
 	 */
-	cfg = kmalloc(sizeof(*cfg), GFP_KERNEL);
-	if (!cfg)
-		return -ENOMEM;
 
-	cfg->pktlen   = 5;
-	cfg->baudrate = kl5kusb105a_sio_b9600;
-	cfg->databits = kl5kusb105a_dtb_8;
-	cfg->unknown1 = 0;
-	cfg->unknown2 = 1;
-	klsi_105_chg_port_settings(port, cfg);
+	cfg.pktlen   = 5;
+	cfg.baudrate = kl5kusb105a_sio_b9600;
+	cfg.databits = kl5kusb105a_dtb_8;
+	cfg.unknown1 = 0;
+	cfg.unknown2 = 1;
+	klsi_105_chg_port_settings(port, &cfg);
 
 	spin_lock_irqsave(&priv->lock, flags);
-	priv->cfg.pktlen   = cfg->pktlen;
-	priv->cfg.baudrate = cfg->baudrate;
-	priv->cfg.databits = cfg->databits;
-	priv->cfg.unknown1 = cfg->unknown1;
-	priv->cfg.unknown2 = cfg->unknown2;
+	priv->cfg.pktlen   = cfg.pktlen;
+	priv->cfg.baudrate = cfg.baudrate;
+	priv->cfg.databits = cfg.databits;
+	priv->cfg.unknown1 = cfg.unknown1;
+	priv->cfg.unknown2 = cfg.unknown2;
 	spin_unlock_irqrestore(&priv->lock, flags);
 
-	kfree(cfg);
-
 	/* READ_ON and urb submission */
 	rc = usb_serial_generic_open(tty, port);
 	if (rc)
-- 
2.17.1