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If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner] .TH USB_PIPE_DRAIN_REQS 9F "Jan 5, 2004" .SH NAME usb_pipe_drain_reqs \- Allow completion of pending pipe requests .SH SYNOPSIS .nf #include \fBint\fR \fBusb_pipe_drain_reqs\fR(\fBdev_info_t *\fR\fIdip\fR, \fBusb_pipe_handle_t\fR \fIpipe_handle\fR, \fBuint_t\fR \fItimeout\fR, \fBusb_flags_t\fR \fIusb_flags\fR, \fBvoid (*\fR\fIcallback\fR)(usb_pipe_handle_t \fIpipe_handle\fR, \fBusb_opaque_t\fR \fIcallback_arg\fR, \fBint\fR \fIrval\fR, \fBusb_cb_flags_t\fR \fIflags)\fR, \fBusb_opaque_t\fR \fIcallback_arg\fR); .fi .SH INTERFACE LEVEL illumos DDI specific (illumos DDI) .SH PARAMETERS .ne 2 .na \fB\fIdip\fR\fR .ad .RS 16n Pointer to the device's \fBdev_info\fR structure. .RE .sp .ne 2 .na \fB\fIpipe_handle\fR\fR .ad .RS 16n Handle of the pipe containing pending requests. .RE .sp .ne 2 .na \fB\fItimeout\fR\fR .ad .RS 16n Maximum wait time for requests to drain. Must be a non-negative value in seconds. Zero specifies no timeout. .RE .sp .ne 2 .na \fB\fIflags\fR\fR .ad .RS 16n USB_FLAGS_SLEEP is the only flag recognized. Wait for completion and do not call callback. .RE .sp .ne 2 .na \fB\fIcallback\fR\fR .ad .RS 16n Callback handler to notify of asynchronous completion. .RE .sp .ne 2 .na \fB\fIcallback_arg\fR\fR .ad .RS 16n Second argument passed to callback function. .RE .SH DESCRIPTION The \fBusb_pipe_drain_reqs()\fR function provides waits for pending requests to complete and then provides synchronous or asynchronous notification that all pending requests on a non-shared pipe indicated by pipe_handle have completed. For a shared pipe (such as the default control pipe used by multiple drivers each managing one interface of a device), this function provides notification that all pending requests on that pipe that are associated with a given dip are completed. .sp .LP The \fBusb_pipe_drain_reqs()\fR function can be used to notify a close procedure when the default control pipe is clear during device closure, thereby allowing the close procedure to continue safely. Normally, a synchronous call to \fBusb_pipe_close\fR(9F) allows all requests in a pipe to finish before returning. However, a client driver cannot close the default control pipe. .sp .LP If USB_FLAGS_SLEEP is set in flags, block until all pending requests are completed. Otherwise, return immediately and call the callback handler when all pending requests are completed. .sp .LP The \fIcallback\fR parameter accepts the asynchronous callback handler, which takes the following arguments: .sp .ne 2 .na \fBusb_pipe_handle_t default_pipe_handle\fR .ad .sp .6 .RS 4n Handle of the pipe to drain. .RE .sp .ne 2 .na \fBusb_opaque_t callback_arg\fR .ad .sp .6 .RS 4n callback_arg specified to \fBusb_pipe_drain_reqs()\fR. .RE .sp .ne 2 .na \fBint rval\fR .ad .sp .6 .RS 4n Request status. .RE .sp .ne 2 .na \fBusb_cb_flags_t callback_flags\fR .ad .sp .6 .RS 4n Status of the queueing operation. Can be: .sp .ne 2 .na \fBUSB_CB_NO_INFO\fR .ad .RS 27n Callback was uneventful. .RE .sp .ne 2 .na \fBUSB_CB_ASYNC_REQ_FAILED\fR .ad .RS 27n Error starting asynchronous request. .RE .RE .SH RETURN VALUES .ne 2 .na \fBUSB_SUCCESS\fR .ad .RS 23n Request is successful. .RE .sp .ne 2 .na \fBUSB_INVALID_ARGS\fR .ad .RS 23n \fIdip\fR argument is \fBNULL\fR. USB_FLAGS_SLEEP is clear and callback is \fBNULL\fR. .RE .sp .ne 2 .na \fBUSB_INVALID_CONTEXT\fR .ad .RS 23n Called from callback context with the USB_FLAGS_SLEEP flag set. .RE .sp .ne 2 .na \fBUSB_INVALID_PIPE\fR .ad .RS 23n Pipe is not open, is closing or is closed. .RE .SH CONTEXT May be called from user or kernel context. .sp .LP 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 \fBusb_callback_flags\fR(9S) for more information on callbacks. .SH EXAMPLES .in +2 .nf mydev_detach(dev_info_t *dip, ddi_detach_cmd_t cmd) { ... ... mydev_state->pipe_state = CLOSED; /* Wait for pending requests of a pipe to finish. Don't timeout. */ (void) usb_pipe_drain_reqs( dip, pipe_handle, 0, USB_FLAGS_SLEEP, NULL, 0); /* * Dismantle streams and tear down this instance, * now that all requests have been sent. */ qprocsoff(q); ... ... ddi_remove_minor_node(dip, NULL); ... ... } .fi .in -2 .SH NOTES For pipes other than the default control pipe, it is recommended to close the pipe using a synchronous \fBusb_pipe_close()\fR. \fBusb_pipe_close()\fR with the USB_FLAGS_SLEEP flag allows any pending requests in that pipe to complete before returning. .sp .LP Do not call \fBusb_pipe_drain_reqs()\fR while additional requests are being submitted by a different thread. This action can stall the calling thread of \fBusb_pipe_drain_reqs()\fR unnecessarily. .SH ATTRIBUTES See \fBattributes\fR(5) for descriptions of the following attributes: .sp .sp .TS box; c | c l | l . ATTRIBUTE TYPE ATTRIBUTE VALUE _ Architecture PCI-based systems _ Interface stability Committed .TE .SH SEE ALSO \fBattributes\fR(5), \fBusb_pipe_close\fR(9F), \fBusb_pipe_reset\fR(9F), \fBusb_callback_flags\fR(9S)