Проект OpenNet: MAN usb_pipe_get_state (9) Ядро (FreeBSD и Linux)

Интерактивная система просмотра системных руководств (man-ов)

usb_pipe_get_state (9)

>> usb_pipe_get_state (9) ( Solaris man: Ядро )

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

Solaris DDI specific (Solaris 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();
   }