USB_CONTROL_MSG

Section: (9)
Updated: 06 August 2003
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NAME

usb_control_msg - Builds a control urb, sends it off and waits for completion

SYNOPSIS

int usb_control_msg (struct usb_device * dev, unsigned int pipe, __u8 request, __u8 requesttype, __u16 value, __u16 index, void * data, __u16 size, int timeout);

ARGUMENTS

dev: pointer to the usb device to send the message to
pipe: endpoint ``pipe'' to send the message to
request: USB message request value
requesttype: USB message request type value
value: USB message value
index: USB message index value
data: pointer to the data to send
size: length in bytes of the data to send
timeout: time in jiffies 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 control message to a specified endpoint and waits for the message to complete, or timeout.

If successful, it returns the number of bytes transferred, otherwise a negative error number.

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.

ABOUT THIS DOCUMENT

This documentation was generated with kernel version 2.6.0.

This document was created by man2html, using the manual pages.
Time: 08:41:33 GMT, April 09, 2004