USB_CLEAR_HALT(9)                         USB Core APIs                         USB_CLEAR_HALT(9)



NAME
       usb_clear_halt - tells device to clear endpoint halt/stall condition

SYNOPSIS
       int usb_clear_halt(struct usb_device * dev, int pipe);

ARGUMENTS
       dev
           device whose endpoint is halted

       pipe
           endpoint “pipe” being cleared

CONTEXT
       !in_interrupt ()

DESCRIPTION
       This is used to clear halt conditions for bulk and interrupt endpoints, as reported by URB
       completion status. Endpoints that are halted are sometimes referred to as being “stalled”.
       Such endpoints are unable to transmit or receive data until the halt status is cleared.
       Any URBs queued for such an endpoint should normally be unlinked by the driver before
       clearing the halt condition, as described in sections 5.7.5 and 5.8.5 of the USB 2.0 spec.

       Note that control and isochronous endpoints don't halt, although control endpoints report
       “protocol stall” (for unsupported requests) using the same status code used to report a
       true stall.

       This call is synchronous, and may not be used in an interrupt context.

RETURN
       Zero on success, or else the status code returned by the underlying usb_control_msg call.

COPYRIGHT
Kernel Hackers Manual 4.8.                 January 2017                         USB_CLEAR_HALT(9)