USB_INTERRUPT_MSG(9) USB Core APIs USB_INTERRUPT_MSG(9)NAMEusb_interrupt_msg - Builds an interrupt urb, sends it off and waits for
completion
SYNOPSIS
int usb_interrupt_msg(struct usb_device * usb_dev, unsigned int pipe,
void * data, int len, int * actual_length,
int timeout);
ARGUMENTS
usb_dev
pointer to the usb device to send the message to
pipe
endpoint “pipe” to send the message to
data
pointer to the data to send
len
length in bytes of the data to send
actual_length
pointer to a location to put the actual length transferred in bytes
timeout
time in msecs to wait for the message to complete before timing out
(if 0 the wait is forever)
CONTEXT
!in_interrupt ()
DESCRIPTION
This function sends a simple interrupt message to a specified endpoint
and waits for the message to complete, or timeout.
If successful, it returns 0, otherwise a negative error number. The
number of actual bytes transferred will be stored in the actual_length
paramater.
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.
COPYRIGHTKernel Hackers Manual 2.6. November 2013 USB_INTERRUPT_MSG(9)
