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

NAME

usb_clr_feature - Clear feature of USB device, interface or endpoint

SYNOPSIS

#include <sys/usb/usba.h>


int usb_clr_feature(dev_info_t *dip,
uint_t request_type, uint_t feature,
uint_t which, usb_flags_t flags,
void (*callback) (usb_pipe_handle_t pipe_handle,
usb_opaque_t callback_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
Pipe handle to device, device interface or endpoint.


request_type
bmRequestType to be used. One of the following:

USB_DEV_REQ_RCPT_DEV - Clear feature on device.

USB_DEV_REQ_RCPT_IF - Clear feature on interface.

USB_DEV_REQ_RCPT_EP - Clear feature on endpoint.


feature
Feature to be cleared. Can be any device-defined
device-, interface-, or endpoint-specific feature,
including the following which are defined in the USB
2.0 specification:

USB_EP_HALT - Clear a HALT on an endpoint.

USB_DEV_REMOTE_WAKEUP - Clear REMOTE_WAKEUP on a
device.

USB_DEV_TEST_MODE - Clear TEST_MODE on a device.


which
Device, interface or endpoint on which to clear the
feature. One of:
Interface number, for interfaces.
Endpoint number, for endpoints.
0 for devices.


flags
USB_FLAGS_SLEEP is the only flag recognized. Wait for
completion and do not call callback.


callback
Callback handler to notify of asynchronous
completion.


callback_arg
Second argument passed to callback handler.

DESCRIPTION

The usb_clr_feature() function clears a specific feature of a device,
interface or endpoint. This function always blocks and waits for
resources if not available, regardless of the flags argument.


This call blocks for completion if USB_FLAGS_SLEEP is set in flags.
It returns immediately and calls the callback upon completion if
USB_FLAGS_SLEEP is not set.

RETURN VALUES

USB_SUCCESS
Feature was successfully cleared.


USB_INVALID_ARGS
dip argument is NULL.


USB_INVALID_PIPE
pipe_handle argument is NULL


USB_INVALID_CONTEXT
Called from interrupt context with
USB_FLAGS_SLEEP flag set.


USB_FAILURE
Clearing of feature was unsuccessful.

CONTEXT

May always be called from user or kernel context. May be called from
interrupt context only if USB_FLAGS_SLEEP is not set in flags.


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

if (usb_clr_feature(dip, pipe_handle, USB_DEV_REQ_RCPT_EP,
USB_EP_HALT, data_endpoint_num, 0) == USB_FAILURE) {
cmn_err (CE_WARN,
"%s%d: Error clearing halt condition on data endpoint %d.",
ddi_driver_name(dip), ddi_get_instance(dip),
data_endpoint_num);
}

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+--------------------+-------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-------------------+
|Architecture | PCI-based systems |
+--------------------+-------------------+
|Interface stability | Committed |
+--------------------+-------------------+

SEE ALSO

attributes(7), usb_get_status(9F), usb_pipe_get_state(9F),
usb_pipe_reset(9F), usb_callback_flags(9S)

February 9, 2004 USB_CLR_FEATURE(9F)