other versions
- wheezy 3.2.78-1
USB_INTERRUPT_MSG(9) | USB Core APIs | USB_INTERRUPT_MSG(9) |
NAME¶
usb_interrupt_msg - Builds an interrupt urb, sends it off and waits for completionSYNOPSIS¶
int
usb_interrupt_msg(struct usb_device * usb_dev,
unsigned int pipe,
void * data, int len,
int * actual_length,
int timeout);
ARGUMENTS¶
usb_devpointer 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.COPYRIGHT¶
March 2016 | Kernel Hackers Manual 3.2. |