illumos: manual page: usb_pipe

USB_PIPE_CLOSE(9F) Kernel Functions for Drivers USB_PIPE_CLOSE(9F)

NAME

usb_pipe_close - Close and cleanup a USB device pipe

SYNOPSIS

#include <sys/usb/usba.h>

void usb_pipe_close(dev_info_t *dip, usb_pipe_handle_t pipe_handle,
usb_flags_t flags,
void (*callback)(usb_pipe_handle_t pipe_handle,
usb_opaque_t arg, int rval,
usb_cb_flags_t flags), usb_opaque_t callback_arg);

INTERFACE LEVEL

illumos DDI specific (illumos DDI)

PARAMETERS

dip
Pointer to the device's dev_info structure.

pipe_handle
Handle of pipe to close. Cannot be a handle to the
default control pipe.

flags
USB_FLAGS_SLEEP is the only flag recognized. Set it to
wait for resources, for pipe to become free, and for all
pending request callbacks to complete.

callback
This function is called on completion if the
USB_FLAGS_SLEEP flag is not specified. Mandatory if the
USB_FLAGS_SLEEP flag has not been specified.

callback_arg
Second argument to callback function.

DESCRIPTION

The usb_pipe_close() function closes the pipe pointed to by pipe_handle,
releases all related resources and then frees the pipe handle. This
function stops polling if the pipe to be closed is an interrupt-IN or
isochronous-IN pipe. The default control pipe cannot be closed.

Pipe cleanup includes waiting for the all pending requests in the pipe to
finish, and then flushing residual requests remaining after waiting for
several seconds. Exception handlers of flushed requests are called with
a completion reason of USB_CR_FLUSHED.

If USB_FLAGS_SLEEP is specified in flags, wait for all cleanup operations
to complete before calling the callback handler and returning.

If USB_FLAGS_SLEEP is not specified in flags, an asynchronous close (to
be done in a separate thread) is requested. Return immediately. The
callback handler is called after all pending operations are completed.

The callback parameter is the callback handler and takes the following
arguments:

usb_pipe_handle_t pipe_handle

Handle of the pipe to close.

usb_opaque_t callback_arg

Callback_arg specified to usb_pipe_close().

int rval

Return value of close operation

usb_cb_flags_t callback_flags

Status of queueing operation. Can be:

USB_CB_NO_INFO
Callback was uneventful.

USB_CB_ASYNC_REQ_FAILED
Error starting asynchronous request.

RETURN VALUES

Status is returned to the caller via the callback handler's rval
argument. Possible callback handler rval argument values are:

USB_INVALID_PIPE
Pipe handle specifies a pipe which is closed or
closing.

USB_INVALID_ARGS
dip or pipe_handle arguments are NULL.

USB_INVALID_CONTEXT
Called from interrupt context.

USB_INVALID_PERM
Pipe handle specifies the default control pipe.

USB_FAILURE
Asynchronous resources are unavailable. In this
case, USB_CB_ASYNC_REQ_FAILED is passed in as the
callback_flags arg to the callback handler.

Exception handlers of any queued requests which were flushed are called
with a completion reason of USB_CR_FLUSHED. Exception handlers of
periodic pipe requests which were terminated are called with
USB_CR_PIPE_CLOSING.

Note that messages mirroring the above errors are logged to the console
logfile on error. (This provides status for calls which otherwise could
provide status).

CONTEXT

May be called from user or kernel context regardless of arguments. May
not be called from a callback executing in interrupt context. Please
see usb_callback_flags(9S) for more information on callbacks.

If the USB_CB_ASYNC_REQ_FAILED bit is clear in usb_cb_flags_t, the
callback, if supplied, can block because it is executing in kernel
context. Otherwise the callback cannot block. Please see
usb_callback_flags(9S) for more information on callbacks.

EXAMPLES

/* Synchronous close of pipe. */
usb_pipe_close(dip, pipe, USB_FLAGS_SLEEP, NULL, NULL);

--------

/* Template callback. */
void close_callback(usb_pipe_handle_t, usb_opaque_t, usb_cb_flags_t);

/* Asynchronous close of pipe. */
usb_pipe_close(dip, pipe, 0, close_callback, callback_arg);

ATTRIBUTES