suse man page for usb_ep_set_halt

USB_EP_SET_HALT(9)					      Kernel Mode Gadget API						USB_EP_SET_HALT(9)

NAME
       usb_ep_set_halt - sets the endpoint halt feature.

SYNOPSIS
       int usb_ep_set_halt(struct usb_ep * ep);

ARGUMENTS
       ep
	   the non-isochronous endpoint being stalled

DESCRIPTION
       Use this to stall an endpoint, perhaps as an error report. Except for control endpoints, the endpoint stays halted (will not stream any
       data) until the host clears this feature; drivers may need to empty the endpoint's request queue first, to make sure no inappropriate
       transfers happen.

       Note that while an endpoint CLEAR_FEATURE will be invisible to the gadget driver, a SET_INTERFACE will not be. To reset endpoints for the
       current altsetting, see usb_ep_clear_halt. When switching altsettings, it's simplest to use usb_ep_enable or usb_ep_disable for the
       endpoints.

       Returns zero, or a negative error code. On success, this call sets underlying hardware state that blocks data transfers. Attempts to halt
       IN endpoints will fail (returning -EAGAIN) if any transfer requests are still queued, or if the controller hardware (usually a FIFO) still
       holds bytes that the host hasn't collected.

AUTHOR
       David Brownell <dbrownell@users.sourceforge.net>
	   Author.

COPYRIGHT
Kernel Hackers Manual 2.6.					     July 2010							USB_EP_SET_HALT(9)