diff mbox series

[06/15] usb: serial: f81232: use usb_control_msg_recv() and usb_control_msg_send()

Message ID 20201104064703.15123-7-himadrispandya@gmail.com
State New
Headers show
Series usb: serial: avoid using usb_control_msg() directly | expand

Commit Message

Himadri Pandya Nov. 4, 2020, 6:46 a.m. UTC
The new usb_control_msg_recv() and usb_control_msg_send() nicely wraps
usb_control_msg() with proper error check. Hence use the wrappers
instead of calling usb_control_msg() directly.

Signed-off-by: Himadri Pandya <himadrispandya@gmail.com>
---
 drivers/usb/serial/f81232.c | 88 ++++++++-----------------------------
 1 file changed, 18 insertions(+), 70 deletions(-)

Comments

Johan Hovold Dec. 4, 2020, 9:49 a.m. UTC | #1
On Wed, Nov 04, 2020 at 12:16:54PM +0530, Himadri Pandya wrote:
> The new usb_control_msg_recv() and usb_control_msg_send() nicely wraps

> usb_control_msg() with proper error check. Hence use the wrappers

> instead of calling usb_control_msg() directly.

> 

> Signed-off-by: Himadri Pandya <himadrispandya@gmail.com>

> ---

>  drivers/usb/serial/f81232.c | 88 ++++++++-----------------------------

>  1 file changed, 18 insertions(+), 70 deletions(-)

> 

> diff --git a/drivers/usb/serial/f81232.c b/drivers/usb/serial/f81232.c

> index 0c7eacc630e0..78107feef8a8 100644

> --- a/drivers/usb/serial/f81232.c

> +++ b/drivers/usb/serial/f81232.c

> @@ -139,71 +139,36 @@ 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);


This driver use tabs for indentation consistently so please stick to
that style. That should also amount to a smaller patch (and less noise
in the logs, e.g. for git blame).

> +	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;

>  }


> @@ -866,32 +831,16 @@ 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) {

> +			/* Retry on error or short transfers */

>  			status = usb_translate_errors(status);

>  			if (status == -EIO)

>  				continue;


So this now depends on the new helper returning an errno on short
transfers which gets mapped to -EIO by usb_translate_errors(). This
works currently (and with my suggested change to use -EREMOTEIO) but
could possibly lead to subtle regressions later.

I don't think we need to worry about it, but just wanted to highlight
the kind of impact these changes can have.

Note that this change also replaces a single memdup with a memdup+memcpy
for each iteration. But as this helper is used rarely (e.g. probe,
resume and disconnect), and hopefully the retries are exceptions, the
overhead could be acceptable.

> -		} else if (status != size) {

> -			/* Retry on short transfers */

> -			status = -EIO;

> -			continue;

> -		} else {

> -			status = 0;

>  		}

>  

>  		break;

> @@ -902,7 +851,6 @@ static int f81534a_ctrl_set_register(struct usb_interface *intf, u16 reg,

>  				reg, status);

>  	}

>  

> -	kfree(tmp);

>  	return status;

>  }


Johan
diff mbox series

Patch

diff --git a/drivers/usb/serial/f81232.c b/drivers/usb/serial/f81232.c
index 0c7eacc630e0..78107feef8a8 100644
--- a/drivers/usb/serial/f81232.c
+++ b/drivers/usb/serial/f81232.c
@@ -139,71 +139,36 @@  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 != sizeof(val)) {
+	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);
 
-		if (status < 0)
-			status = usb_translate_errors(status);
-		else
-			status = -EIO;
-	} else {
-		status = 0;
+		status = usb_translate_errors(status);
 	}
-
-	kfree(tmp);
 	return status;
 }
 
@@ -866,32 +831,16 @@  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) {
+			/* Retry on error or short transfers */
 			status = usb_translate_errors(status);
 			if (status == -EIO)
 				continue;
-		} else if (status != size) {
-			/* Retry on short transfers */
-			status = -EIO;
-			continue;
-		} else {
-			status = 0;
 		}
 
 		break;
@@ -902,7 +851,6 @@  static int f81534a_ctrl_set_register(struct usb_interface *intf, u16 reg,
 				reg, status);
 	}
 
-	kfree(tmp);
 	return status;
 }