From d18960494f65ca4fa0d67c865aaca99452070d15 Mon Sep 17 00:00:00 2001 From: Thomas Renninger Date: Wed, 3 Nov 2010 17:06:14 +0100 Subject: ACPI, intel_idle: Cleanup idle= internal variables 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 cc: x86@kernel.org Signed-off-by: Len Brown --- drivers/acpi/processor_core.c | 4 ++-- drivers/acpi/processor_idle.c | 24 +++++++++++------------- drivers/idle/intel_idle.c | 4 ++++ 3 files changed, 17 insertions(+), 15 deletions(-) (limited to 'drivers') diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c index bec561c..3c1a2fe 100644 --- a/drivers/acpi/processor_core.c +++ b/drivers/acpi/processor_core.c @@ -23,7 +23,7 @@ static int set_no_mwait(const struct dmi_system_id *id) { printk(KERN_NOTICE PREFIX "%s detected - " "disabling mwait for CPU C-states\n", id->ident); - idle_nomwait = 1; + boot_option_idle_override = IDLE_NOMWAIT; return 0; } @@ -283,7 +283,7 @@ acpi_processor_eval_pdc(acpi_handle handle, struct acpi_object_list *pdc_in) { acpi_status status = AE_OK; - if (idle_nomwait) { + if (boot_option_idle_override == IDLE_NOMWAIT) { /* * If mwait is disabled for CPU C-states, the C2C3_FFH access * mode will be disabled in the parameter of _PDC object. diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index dcb38f8..eefd4aa 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -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); diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index 94a6526..21d3871 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -404,6 +404,10 @@ static int __init intel_idle_init(void) { int retval; + /* Do not load intel_idle at all for now if idle= is passed */ + if (boot_option_idle_override != IDLE_NO_OVERRIDE) + return -ENODEV; + retval = intel_idle_probe(); if (retval) return retval; -- cgit v1.1