On Wed, Nov 04, 2020 at 12:16:52PM +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.
This too is a good example of when the new helpers can be used, but
please mention the transfer buffers here are that is the primary reason.
> Signed-off-by: Himadri Pandya <himadrispandya@xxxxxxxxx>
> ---
> drivers/usb/serial/cp210x.c | 148 ++++++++++--------------------------
> 1 file changed, 42 insertions(+), 106 deletions(-)
>
> diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
> index d0c05aa8a0d6..29436ab392e8 100644
> --- a/drivers/usb/serial/cp210x.c
> +++ b/drivers/usb/serial/cp210x.c
> @@ -555,31 +555,15 @@ static int cp210x_read_reg_block(struct usb_serial_port *port, u8 req,
> {
> struct usb_serial *serial = port->serial;
> struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
> - void *dmabuf;
> int result;
>
> - dmabuf = kmalloc(bufsize, GFP_KERNEL);
> - if (!dmabuf) {
> - /*
> - * FIXME Some callers don't bother to check for error,
> - * at least give them consistent junk until they are fixed
> - */
> - memset(buf, 0, bufsize);
> - return -ENOMEM;
> - }
> -
> - result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
> - req, REQTYPE_INTERFACE_TO_HOST, 0,
> - port_priv->bInterfaceNumber, dmabuf, bufsize,
> - USB_CTRL_SET_TIMEOUT);
> - if (result == bufsize) {
> - memcpy(buf, dmabuf, bufsize);
> - result = 0;
> - } else {
> + result = usb_control_msg_recv(serial->dev, 0, req,
> + REQTYPE_INTERFACE_TO_HOST, 0,
> + port_priv->bInterfaceNumber, buf, bufsize,
> + USB_CTRL_SET_TIMEOUT, GFP_KERNEL);
Please keep the existing indentation style. That way you don't need to
change the middle-two argument lines just to align the arguments.
> + if (result) {
> dev_err(&port->dev, "failed get req 0x%x size %d status: %d\n",
> - req, bufsize, result);
> - if (result >= 0)
> - result = -EIO;
> + req, bufsize, result);
Nit: This is an unrelated indentation change.
>
> /*
> * FIXME Some callers don't bother to check for error,
> @@ -588,8 +572,6 @@ static int cp210x_read_reg_block(struct usb_serial_port *port, u8 req,
> memset(buf, 0, bufsize);
> }
>
> - kfree(dmabuf);
> -
> return result;
> }
>
> @@ -648,29 +630,16 @@ static int cp210x_read_u8_reg(struct usb_serial_port *port, u8 req, u8 *val)
> static int cp210x_read_vendor_block(struct usb_serial *serial, u8 type, u16 val,
> void *buf, int bufsize)
> {
> - void *dmabuf;
> int result;
>
> - dmabuf = kmalloc(bufsize, GFP_KERNEL);
> - if (!dmabuf)
> - return -ENOMEM;
> -
> - result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
> - CP210X_VENDOR_SPECIFIC, type, val,
> - cp210x_interface_num(serial), dmabuf, bufsize,
> - USB_CTRL_GET_TIMEOUT);
> - if (result == bufsize) {
> - memcpy(buf, dmabuf, bufsize);
> - result = 0;
> - } else {
> + result = usb_control_msg_recv(serial->dev, 0, CP210X_VENDOR_SPECIFIC,
> + type, val, cp210x_interface_num(serial),
> + buf, bufsize, USB_CTRL_GET_TIMEOUT,
> + GFP_KERNEL);
> + if (result)
> dev_err(&serial->interface->dev,
> "failed to get vendor val 0x%04x size %d: %d\n", val,
> bufsize, result);
> - if (result >= 0)
> - result = -EIO;
> - }
Nit: Please keep the brackets around multiline single statements since
it improves readability.
Similar comments apply to the rest of the patch.
Johan
