Tribblix: manual page: usba_hcdi_dup_intr

USBA_HCDI_DUP_INTER_REQ(9F) Kernel Functions for Drivers

NAME

usba_hcdi_dup_intr_req - duplicate an interrupt request

SYNOPSIS

#include <sys/usb/usba/hcdi.h>

usb_intr_req_t *
usba_hcdi_dup_intr_req(dev_info_t *dip, usb_intr_req_t *irqp,
size_t size, usb_flags_t flags);

INTERFACE LEVEL

Volatile - illumos USB HCD private function

This is a private function that is not part of the stable DDI. It may
be removed or changed at any time.

PARAMETERS

dip A pointer to the HCD driver's dev_info structure.

irqp A pointer to the USB interrupt request which will be
duplicated.

size The number of bytes in the allocated data block mblk_t.

flags Flags which describe how allocations should be performed.
Valid flags are:

USB_FLAGS_NOSLEEP
Do not block waiting for memory. If memory is
not available the allocation will fail.

USB_FLAGS_SLEEP
Perform a blocking allocation. If memory is not
available, the function will wait until memory is
made available.

Note, the request may still fail even if
USB_FLAGS_SLEEP is specified.

DESCRIPTION

The usba_hcdi_dup_intr_req() function is used to duplicate an existing
interrupt request, irqp.

The USBA framework initiates interrupt operations through the
usba_hcdi_pipe_intr_xfer(9E) entry point. It provides an initial USB
interrupt request as an argument. When the HCD driver has interrupt
data to return, it needs to duplicate that initial interrupt request
each time that it submits data through the usba_hcdi_cb(9F) function.
In addition to duplicating the request, callers may also need to
increase the pipe handle's request count. For more information, see
usba_hcdi_pipe_intr_xfer(9E).

The dip argument should correspond to the HCD driver's dev_info_t
structure. The irqp pointer should correspond to the initial interrupt
request. The size argument should describe the maximum amount of data
needed for this request. The amount of data will be dependent on the
endpoint and device. The value of flags should depend on the caller's
context. If USB_FLAGS_SLEEP is passed while in interrupt context, then
this function will fail.

CONTEXT

The usba_hcdi_dup_intr_req() function may be called from user, kernel,
or interrupt context; however, when in interrupt context, the value of
flags must be USB_FLAGS_NOSLEEP.

RETURN VALUES

Upon successful completion, the usba_hcdi_dup_intr_req() function
returns a pointer to a duplicated interrupt request. Otherwise, NULL
is returned to indicate that the request could not be duplicated.