usb_interrupt_msg (9) - Linux Man Pages
usb_interrupt_msg: Builds an interrupt urb, sends it off and waits for completion
usb_interrupt_msg - Builds an interrupt urb, sends it off and waits for completion
int usb_interrupt_msg(struct usb_device
*usb_dev, unsigned int pipe, void *data, int len, int *actual_length, int timeout);
- pointer to the usb device to send the message to
- endpoint "pipe" to send the message to
- pointer to the data to send
- length in bytes of the data to send
- pointer to a location to put the actual length transferred in bytes
- time in msecs to wait for the message to complete before timing out (if 0 the wait is forever)
This function sends a simple interrupt message to a specified endpoint and waits for the message to complete, or timeout.
Don't use this function from within an interrupt context, like a bottom half handler. If you need an asynchronous message, or need to send a message from within interrupt context, use usb_submit_urb If a thread in your driver uses this call, make sure your disconnect method can wait for it to complete. Since you don't have a handle on the URB used, you can't cancel the request.