usb_interrupt_msg (9) - Linux Manuals
usb_interrupt_msg: Builds an interrupt urb, sends it off and waits for completion
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 intpipe, void * data, intlen, int * actual_length, inttimeout);
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
DESCRIPTION
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.
RETURN
If successful, 0. Otherwise a negative error number. The number of actual bytes transferred will be stored in the actual_length parameter.
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