Re: [PATCH v2 1/3] USB: serial: return errors from break handling

Oliver Neukum
2023-06-06T11:13:41Z

On 04.06.23 14:35, Johan Hovold wrote:
> @@ -1077,15 +1077,19 @@ static void pl2303_set_break(struct usb_serial_port *port, bool enable)
> result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
> BREAK_REQUEST, BREAK_REQUEST_TYPE, state,
> 0, NULL, 0, 100);
> - if (result)
> + if (result) {
> dev_err(&port->dev, "error sending break = %d\n", result);
> + return result;
> + }
> +
> + return 0;
> }

Hi,

this code was always fishy, but I am afraid it worked by accident albeit
spamming the logs.
If I may quote from the kerneldoc of usb_control_msg():

* usb_control_msg - Builds a control urb, sends it off and waits for completion

[..]

* Return: If successful, the number of bytes transferred. Otherwise, a negative
* error number.
*/

You need to test for < 0, not != 0

Regards
Oliver