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

usb_clr_feature - Clear feature of USB device, interface or endpoint

#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);

illumos DDI specific (illumos DDI)

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.

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.

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.

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.


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);
   }

See attributes(5) for descriptions of the following attributes:

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

attributes(5), usb_get_status(9F), usb_pipe_reset(9F), usb_pipe_get_state(9F), usb_callback_flags(9S)
February 9, 2004 OmniOS