Tribblix: manual page: usb_pipe_get

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

NAME

usb_pipe_get_state - Return USB pipe state

SYNOPSIS

#include <sys/usb/usba.h>

int usb_pipe_get_state(usb_pipe_handle_t pipe_handle,
usb_pipe_state_t *pipe_state, usb_flags_t usb_flags);

INTERFACE LEVEL

illumos DDI specific (illumos DDI)

PARAMETERS

pipe_handle
Handle of the pipe to retrieve the state.

pipe_state
Pointer to where pipe state is returned.

usb_flags
No flags are recognized. Reserved for future
expansion.

DESCRIPTION

The usb_pipe_get_state() function retrieves the state of the pipe
referred to by pipe_handle into the location pointed to by
pipe_state.

Possible pipe states are:

USB_PIPE_STATE_CLOSED
Pipe is closed.

USB_PIPE_STATE_ACTIVE
Pipe is active and can send/receive data.
Polling is active for isochronous and
interrupt pipes.

USB_PIPE_STATE_IDLE
Polling is stopped for isochronous and
interrupt-IN pipes.

USB_PIPE_STATE_ERROR
An error occurred. Client must call
usb_pipe_reset(). Note that this status is
not seen by a client driver if
USB_ATTRS_AUTOCLEARING is set in the
request attributes.

USB_PIPE_STATE_CLOSING
Pipe is being closed. Requests are being
drained from the pipe and other cleanup is
in progress.

RETURN VALUES

USB_SUCCESS
Pipe state returned in second argument.

USB_INVALID_ARGS
Pipe_state argument is NULL.

USB_INVALID_PIPE
Pipe_handle argument is NULL.

CONTEXT

May be called from user, kernel or interrupt context.

EXAMPLES

usb_pipe_handle_t pipe;
usb_pipe_state_t state;

/* Recover if the pipe is in an error state. */
if ((usb_pipe_get_state(pipe, &state, 0) == USB_SUCCESS) &&
(state == USB_PIPE_STATE_ERROR)) {
cmn_err (CE_WARN, "%s%d: USB Pipe error.",
ddi_driver_name(dip), ddi_get_instance(dip));
do_recovery();
}

ATTRIBUTES