From c75de0ac0756d4b442f460e10461720c7c2412c2 Mon Sep 17 00:00:00 2001 From: Viresh Kumar Date: Thu, 2 Apr 2015 10:21:33 +0530 Subject: cpufreq: Schedule work for the first-online CPU on resume All CPUs leaving the first-online CPU are hotplugged out on suspend and and cpufreq core stops managing them. On resume, we need to call cpufreq_update_policy() for this CPU's policy to make sure its frequency is in sync with cpufreq's cached value, as it might have got updated by hardware during suspend/resume. The policies are always added to the top of the policy-list. So, in normal circumstances, CPU 0's policy will be the last one in the list. And so the code checks for the last policy. But there are cases where it will fail. Consider quad-core system, with policy-per core. If CPU0 is hotplugged out and added back again, the last policy will be on CPU1 :( To fix this in a proper way, always look for the policy of the first online CPU. That way we will be sure that we are calling cpufreq_update_policy() for the only CPU that wasn't hotplugged out. Cc: 3.15+ # 3.15+ Fixes: 2f0aea936360 ("cpufreq: suspend governors on system suspend/hibernate") Reported-by: Saravana Kannan Signed-off-by: Viresh Kumar Acked-by: Saravana Kannan Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/cpufreq.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) (limited to 'drivers') diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 28e59a48b35f..8ae655c364f4 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -1698,15 +1698,18 @@ void cpufreq_resume(void) || __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS)) pr_err("%s: Failed to start governor for policy: %p\n", __func__, policy); - - /* - * schedule call cpufreq_update_policy() for boot CPU, i.e. last - * policy in list. It will verify that the current freq is in - * sync with what we believe it to be. - */ - if (list_is_last(&policy->policy_list, &cpufreq_policy_list)) - schedule_work(&policy->update); } + + /* + * schedule call cpufreq_update_policy() for first-online CPU, as that + * wouldn't be hotplugged-out on suspend. It will verify that the + * current freq is in sync with what we believe it to be. + */ + policy = cpufreq_cpu_get_raw(cpumask_first(cpu_online_mask)); + if (WARN_ON(!policy)) + return; + + schedule_work(&policy->update); } /** -- cgit v1.2.3 From d75e4af14e228bbe3f86e29bcecb8e6be98d4e04 Mon Sep 17 00:00:00 2001 From: Bartlomiej Zolnierkiewicz Date: Tue, 31 Mar 2015 20:15:09 +0200 Subject: cpuidle: remove state_count field from struct cpuidle_device Thomas Schlichter reports the following issue on his Samsung NC20: "The C-states C1 and C2 to the OS when connected to AC, and additionally provides the C3 C-state when disconnected from AC. However, the number of C-states shown in sysfs is fixed to the number of C-states present at boot. If I boot with AC connected, I always only see the C-states up to C2 even if I disconnect AC. The reason is commit 130a5f692425 (ACPI / cpuidle: remove dev->state_count setting). It removes the update of dev->state_count, but sysfs uses exactly this variable to show the C-states. The fix is to use drv->state_count in sysfs. As this is currently the last user of dev->state_count, this variable can be completely removed." Remove dev->state_count as per the above. Reported-by: Thomas Schlichter Signed-off-by: Bartlomiej Zolnierkiewicz Signed-off-by: Kyungmin Park Acked-by: Daniel Lezcano Cc: 3.14+ # 3.14+ [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki --- drivers/cpuidle/cpuidle.c | 3 --- drivers/cpuidle/sysfs.c | 5 +++-- 2 files changed, 3 insertions(+), 5 deletions(-) (limited to 'drivers') diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 080bd2dbde4b..7a73a279e179 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -330,9 +330,6 @@ int cpuidle_enable_device(struct cpuidle_device *dev) if (!dev->registered) return -EINVAL; - if (!dev->state_count) - dev->state_count = drv->state_count; - ret = cpuidle_add_device_sysfs(dev); if (ret) return ret; diff --git a/drivers/cpuidle/sysfs.c b/drivers/cpuidle/sysfs.c index 97c5903b4606..832a2c3f01ff 100644 --- a/drivers/cpuidle/sysfs.c +++ b/drivers/cpuidle/sysfs.c @@ -401,7 +401,7 @@ static int cpuidle_add_state_sysfs(struct cpuidle_device *device) struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device); /* state statistics */ - for (i = 0; i < device->state_count; i++) { + for (i = 0; i < drv->state_count; i++) { kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL); if (!kobj) goto error_state; @@ -433,9 +433,10 @@ error_state: */ static void cpuidle_remove_state_sysfs(struct cpuidle_device *device) { + struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device); int i; - for (i = 0; i < device->state_count; i++) + for (i = 0; i < drv->state_count; i++) cpuidle_free_state_kobj(device, i); } -- cgit v1.2.3 From c7e8bdf5872c5a8f5a6494e16fe839c38a0d3d3d Mon Sep 17 00:00:00 2001 From: Thomas Schlichter Date: Tue, 31 Mar 2015 20:24:39 +0200 Subject: cpuidle: ACPI: do not overwrite name and description of C0 Fix a bug that leads to showing the name and description of C-state C0 as "" in sysfs after the ACPI C-states changed (e.g. after AC->DC or DC->AC transition). The function poll_idle_init() in drivers/cpuidle/driver.c initializes the state 0 during cpuidle_register_driver(), so we better do not overwrite it again with '\0' during acpi_processor_cst_has_changed(). Signed-off-by: Thomas Schlichter Reviewed-by: Bartlomiej Zolnierkiewicz Cc: 3.13+ # 3.13+ Signed-off-by: Rafael J. Wysocki --- drivers/acpi/processor_idle.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index c6bb9f1257c9..f98db0b50551 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -922,7 +922,7 @@ static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr) return -EINVAL; drv->safe_state_index = -1; - for (i = 0; i < CPUIDLE_STATE_MAX; i++) { + for (i = CPUIDLE_DRIVER_STATE_START; i < CPUIDLE_STATE_MAX; i++) { drv->states[i].name[0] = '\0'; drv->states[i].desc[0] = '\0'; } -- cgit v1.2.3