i_enable Kernel Service
Purpose
Enables interrupt priorities.
Syntax
#include <sys/types.h>
#include <sys/errno.h>
#include <sys/intr.h>void i_enable ( old)
int old;
int old;
Parameter
| Item | Description |
|---|---|
| old | Specifies the interrupt priority returned by the i_disable service. |
Description
The i_enable service restores the interrupt priority to a less-favored value. This value should be the value that was in effect before the corresponding call to the i_disable service.
Note: When
serializing a thread with an interrupt handler in a multiprocessor-safe
kernel extension, locking must be used as well as interrupt control.
For this reason, new code should call the unlock_enable kernel
service instead of i_enable. The unlock_enable service
performs locking only on multiprocessor systems, and helps ensure
that code is portable between uniprocessor and multiprocessor systems.
Execution Environment
The i_enable kernel service can be called from either the process or interrupt environment.
Return Values
The i_enable service has no return values.