On Fri, May 01, 2020 at 12:19:23AM +0530, mani@xxxxxxxxxx wrote:
> +static int xr_set_reg(struct usb_serial_port *port, u8 block, u8 reg,
> + u8 val)
> +{
> + struct usb_serial *serial = port->serial;
> + int ret = -EINVAL;
> +
> + /* XR21V141X uses custom command for writing UART registers */
> + ret = usb_control_msg(serial->dev,
> + usb_sndctrlpipe(serial->dev, 0),
> + XR_SET_XR21V141X,
> + USB_DIR_OUT | USB_TYPE_VENDOR, val,
> + reg | (block << 8), NULL, 0,
> + USB_CTRL_SET_TIMEOUT);
> +
> + if (ret < 0)
> + dev_err(&port->dev, "Failed to set reg 0x%x status: %d\n",
> + reg, ret);
> +
> + return ret;
> +}
So if this call is successful, it would return the number of bytes
written in the control message. Which is 0. But that's kind of a hack,
right? Why not just return 0 to make it more obvious and easier to
read, instead of returning 'ret' and making the reader have to realize
that you only are writing 0 bytes?
> +
> +static int xr_get_reg(struct usb_serial_port *port, u8 block, u8 reg,
> + u8 *val)
> +{
> + struct usb_serial *serial = port->serial;
> + void *dmabuf;
char *dmabuf; ?
> + int ret = -EINVAL;
> +
> + dmabuf = kmalloc(1, GFP_KERNEL);
> + if (!dmabuf)
> + return -ENOMEM;
> +
> + /* XR21V141X uses custom command for reading UART registers */
> + ret = usb_control_msg(serial->dev,
> + usb_rcvctrlpipe(serial->dev, 0),
> + XR_GET_XR21V141X,
> + USB_DIR_IN | USB_TYPE_VENDOR, 0,
> + reg | (block << 8), dmabuf, 1,
> + USB_CTRL_SET_TIMEOUT);
> +
> + if (ret == 1) {
> + memcpy(val, dmabuf, 1);
*val = *dmabuf; ?
> + ret = 0;
> + } else {
> + dev_err(&port->dev, "Failed to get reg 0x%x status: %d\n",
> + reg, ret);
> + if (ret >= 0)
> + ret = -EIO;
> + }
> +
> + kfree(dmabuf);
> +
> + return ret;
> +}
Anyway, other than these minor things, this looks good to me:
Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
