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

NAME

pm_busy_component, pm_idle_component - control device component
availability for Power Management

SYNOPSIS

#include <sys/ddi.h>
#include <sys/sunddi.h>


int pm_busy_component(dev_info_t *dip, int component);


int pm_idle_component(dev_info_t *dip, int component);

INTERFACE LEVEL

illumos DDI specific (illumos DDI)

PARAMETERS

dip
Pointer to the device's dev_info structure.


component
The number of the component to be power-managed.

DESCRIPTION

The pm_busy_component() function sets component of dip to be busy. Calls
to pm_busy_component() are stacked, requiring a corresponding number of
calls to pm_idle_component() to make the component idle again. When a
device is busy it will not be power-managed by the system.


The pm_idle_component() function marks component idle, recording the time
that component went idle. This function must be called once for each call
to pm_busy_component(). A component which is idle is available to be
power-managed by the system. The pm_idle_component() function has no
effect if the component is already idle, except to update the system's
notion of when the device went idle.


If these functions are called as a result of entry into the driver's
attach(9E), detach(9E) or power(9E) entry point, these functions must be
called from the same thread which entered attach(9E), detach(9E) or
power(9E).

RETURN VALUES

The pm_busy_component() and pm_idle_component() functions return:

DDI_SUCCESS
Successfully set the indicated component busy or idle.


DDI_FAILURE
Invalid component number component or the device has no
components.

CONTEXT

These functions can be called from user or kernel context. These
functions may also be called from interrupt context, providing they are
not the first Power Management function called by the driver.

ATTRIBUTES

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


+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Interface stability | Committed |
+--------------------+-----------------+

SEE ALSO

pm(4D), power.conf(5), attach(9E), detach(9E), power(9E),
pm_raise_power(9F), pm(9P), pm-components(9P)


Writing Device Drivers


July 21, 2004 PM_BUSY_COMPONENT(9F)