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ACPI, intel_idle: Cleanup idle= internal variables

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Having four variables for the same thing:
  idle_halt, idle_nomwait, force_mwait and boot_option_idle_overrides
is rather confusing and unnecessary complex.

if idle= boot param is passed, only set up one variable:
boot_option_idle_overrides

Introduces following functional changes/fixes:
  - intel_idle driver does not register if any idle=xy
    boot param is passed.
  - processor_idle.c will also not register a cpuidle driver
    and get active if idle=halt is passed.
    Before a cpuidle driver with one (C1, halt) state got registered
    Now the default_idle function will be used which finally uses
    the same idle call to enter sleep state (safe_halt()), but
    without registering a whole cpuidle driver.

That means idle= param will always avoid cpuidle drivers to register
with one exception (same behavior as before):
idle=nomwait
may still register acpi_idle cpuidle driver, but C1 will not use
mwait, but hlt. This can be a workaround for IO based deeper sleep
states where C1 mwait causes problems.

Signed-off-by: Thomas Renninger <trenn@suse.de>
cc: x86@kernel.org
Signed-off-by: Len Brown <len.brown@intel.com>
This commit is contained in:
Thomas Renninger
2010-11-03 17:06:14 +01:00
committed by Len Brown
parent d8c216cfa5
commit d18960494f
7 changed files with 32 additions and 40 deletions
Download Patch File Download Diff File Expand all files Collapse all files

24
drivers/acpi/processor_idle.c
View File

@@ -79,6 +79,13 @@ module_param(bm_check_disable, uint, 0000);
static unsigned int latency_factor __read_mostly = 2;
module_param(latency_factor, uint, 0644);
static int disabled_by_idle_boot_param(void)
{
return boot_option_idle_override == IDLE_POLL ||
boot_option_idle_override == IDLE_FORCE_MWAIT ||
boot_option_idle_override == IDLE_HALT;
}
/*
* IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
* For now disable this. Probably a bug somewhere else.
@@ -455,7 +462,7 @@ static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
continue;
}
if (cx.type == ACPI_STATE_C1 &&
(idle_halt || idle_nomwait)) {
(boot_option_idle_override == IDLE_NOMWAIT)) {
/*
* In most cases the C1 space_id obtained from
* _CST object is FIXED_HARDWARE access mode.
@@ -1058,7 +1065,7 @@ int acpi_processor_cst_has_changed(struct acpi_processor *pr)
{
int ret = 0;
if (boot_option_idle_override)
if (disabled_by_idle_boot_param())
return 0;
if (!pr)
@@ -1089,19 +1096,10 @@ int __cpuinit acpi_processor_power_init(struct acpi_processor *pr,
acpi_status status = 0;
static int first_run;
if (boot_option_idle_override)
if (disabled_by_idle_boot_param())
return 0;
if (!first_run) {
if (idle_halt) {
/*
* When the boot option of "idle=halt" is added, halt
* is used for CPU IDLE.
* In such case C2/C3 is meaningless. So the max_cstate
* is set to one.
*/
max_cstate = 1;
}
dmi_check_system(processor_power_dmi_table);
max_cstate = acpi_processor_cstate_check(max_cstate);
if (max_cstate < ACPI_C_STATES_MAX)
@@ -1142,7 +1140,7 @@ int __cpuinit acpi_processor_power_init(struct acpi_processor *pr,
int acpi_processor_power_exit(struct acpi_processor *pr,
struct acpi_device *device)
{
if (boot_option_idle_override)
if (disabled_by_idle_boot_param())
return 0;
cpuidle_unregister_device(&pr->power.dev);