usb_interrupt_msg(9)
NAME
usb_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.
Donīt 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 donīt have a handle on the URB used,
you canīt cancel the request.