{
u32 eax, ebx, ecx, edx;
- /* User has disallowed the use of MWAIT. Fallback to HALT */
- if (boot_option_idle_override == IDLE_NOMWAIT)
+ /* If override is enforced on the command line, fall back to HALT. */
+ if (boot_option_idle_override != IDLE_NO_OVERRIDE)
return 0;
/* MWAIT is not supported on this platform. Fallback to HALT */
boot_option_idle_override = IDLE_POLL;
cpu_idle_poll_ctrl(true);
} else if (!strcmp(str, "halt")) {
- /*
- * When the boot option of idle=halt is added, halt is
- * forced to be used for CPU idle. In such case CPU C2/C3
- * won't be used again.
- * To continue to load the CPU idle driver, don't touch
- * the boot_option_idle_override.
- */
- static_call_update(x86_idle, default_idle);
+ /* 'idle=halt' HALT for idle. C-states are disabled. */
boot_option_idle_override = IDLE_HALT;
} else if (!strcmp(str, "nomwait")) {
- /*
- * If the boot option of "idle=nomwait" is added,
- * it means that mwait will be disabled for CPU C1/C2/C3
- * states.
- */
+ /* 'idle=nomwait' disables MWAIT for idle */
boot_option_idle_override = IDLE_NOMWAIT;
- } else
- return -1;
+ } else {
+ return -EINVAL;
+ }
return 0;
}