From 20f97caf1120bd02e8ff4adbad3b44b63626feb5 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 13 Oct 2017 15:27:24 +0200 Subject: PM / QoS: Drop PM_QOS_FLAG_REMOTE_WAKEUP The PM QoS flag PM_QOS_FLAG_REMOTE_WAKEUP is not used consistently and the vast majority of code simply assumes that remote wakeup should be enabled for devices in runtime suspend if they can generate wakeup signals, so drop it. Signed-off-by: Rafael J. Wysocki Acked-by: Ulf Hansson Reviewed-by: Mika Westerberg --- Documentation/ABI/testing/sysfs-devices-power | 16 --------------- Documentation/power/pm_qos_interface.txt | 13 ++++++------- drivers/acpi/device_pm.c | 6 ++---- drivers/base/power/domain.c | 4 +--- drivers/base/power/sysfs.c | 28 --------------------------- include/linux/pm_qos.h | 1 - 6 files changed, 9 insertions(+), 59 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-devices-power b/Documentation/ABI/testing/sysfs-devices-power index 676fdf5f2a99..f4b24c327665 100644 --- a/Documentation/ABI/testing/sysfs-devices-power +++ b/Documentation/ABI/testing/sysfs-devices-power @@ -258,19 +258,3 @@ Description: This attribute has no effect on system-wide suspend/resume and hibernation. - -What: /sys/devices/.../power/pm_qos_remote_wakeup -Date: September 2012 -Contact: Rafael J. Wysocki -Description: - The /sys/devices/.../power/pm_qos_remote_wakeup attribute - is used for manipulating the PM QoS "remote wakeup required" - flag. If set, this flag indicates to the kernel that the - device is a source of user events that have to be signaled from - its low-power states. - - Not all drivers support this attribute. If it isn't supported, - it is not present. - - This attribute has no effect on system-wide suspend/resume and - hibernation. diff --git a/Documentation/power/pm_qos_interface.txt b/Documentation/power/pm_qos_interface.txt index 21d2d48f87a2..19c5f7b1a7ba 100644 --- a/Documentation/power/pm_qos_interface.txt +++ b/Documentation/power/pm_qos_interface.txt @@ -98,8 +98,7 @@ Values are updated in response to changes of the request list. The target values of resume latency and active state latency tolerance are simply the minimum of the request values held in the parameter list elements. The PM QoS flags aggregate value is a gather (bitwise OR) of all list elements' -values. Two device PM QoS flags are defined currently: PM_QOS_FLAG_NO_POWER_OFF -and PM_QOS_FLAG_REMOTE_WAKEUP. +values. One device PM QoS flag is defined currently: PM_QOS_FLAG_NO_POWER_OFF. Note: The aggregated target values are implemented in such a way that reading the aggregated value does not require any locking mechanism. @@ -153,14 +152,14 @@ PM QoS list of resume latency constraints and remove sysfs attribute pm_qos_resume_latency_us from the device's power directory. int dev_pm_qos_expose_flags(device, value) -Add a request to the device's PM QoS list of flags and create sysfs attributes -pm_qos_no_power_off and pm_qos_remote_wakeup under the device's power directory -allowing user space to change these flags' value. +Add a request to the device's PM QoS list of flags and create sysfs attribute +pm_qos_no_power_off under the device's power directory allowing user space to +change the value of the PM_QOS_FLAG_NO_POWER_OFF flag. void dev_pm_qos_hide_flags(device) Drop the request added by dev_pm_qos_expose_flags() from the device's PM QoS list -of flags and remove sysfs attributes pm_qos_no_power_off and pm_qos_remote_wakeup -under the device's power directory. +of flags and remove sysfs attribute pm_qos_no_power_off from the device's power +directory. Notification mechanisms: The per-device PM QoS framework has a per-device notification tree. diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c index fbcc73f7a099..e8c820129797 100644 --- a/drivers/acpi/device_pm.c +++ b/drivers/acpi/device_pm.c @@ -581,8 +581,7 @@ static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev, d_min = ret; wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid && adev->wakeup.sleep_state >= target_state; - } else if (dev_pm_qos_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP) != - PM_QOS_FLAGS_NONE) { + } else { wakeup = adev->wakeup.flags.valid; } @@ -865,8 +864,7 @@ int acpi_dev_runtime_suspend(struct device *dev) if (!adev) return 0; - remote_wakeup = dev_pm_qos_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP) > - PM_QOS_FLAGS_NONE; + remote_wakeup = acpi_device_can_wakeup(adev); if (remote_wakeup) { error = acpi_device_wakeup_enable(adev, ACPI_STATE_S0); if (error) diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index e8ca5e2cf1e5..e6414e9998bb 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -346,9 +346,7 @@ static int genpd_power_off(struct generic_pm_domain *genpd, bool one_dev_on, list_for_each_entry(pdd, &genpd->dev_list, list_node) { enum pm_qos_flags_status stat; - stat = dev_pm_qos_flags(pdd->dev, - PM_QOS_FLAG_NO_POWER_OFF - | PM_QOS_FLAG_REMOTE_WAKEUP); + stat = dev_pm_qos_flags(pdd->dev, PM_QOS_FLAG_NO_POWER_OFF); if (stat > PM_QOS_FLAGS_NONE) return -EBUSY; diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c index 156ab57bca77..29bf28fef136 100644 --- a/drivers/base/power/sysfs.c +++ b/drivers/base/power/sysfs.c @@ -309,33 +309,6 @@ static ssize_t pm_qos_no_power_off_store(struct device *dev, static DEVICE_ATTR(pm_qos_no_power_off, 0644, pm_qos_no_power_off_show, pm_qos_no_power_off_store); -static ssize_t pm_qos_remote_wakeup_show(struct device *dev, - struct device_attribute *attr, - char *buf) -{ - return sprintf(buf, "%d\n", !!(dev_pm_qos_requested_flags(dev) - & PM_QOS_FLAG_REMOTE_WAKEUP)); -} - -static ssize_t pm_qos_remote_wakeup_store(struct device *dev, - struct device_attribute *attr, - const char *buf, size_t n) -{ - int ret; - - if (kstrtoint(buf, 0, &ret)) - return -EINVAL; - - if (ret != 0 && ret != 1) - return -EINVAL; - - ret = dev_pm_qos_update_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP, ret); - return ret < 0 ? ret : n; -} - -static DEVICE_ATTR(pm_qos_remote_wakeup, 0644, - pm_qos_remote_wakeup_show, pm_qos_remote_wakeup_store); - #ifdef CONFIG_PM_SLEEP static const char _enabled[] = "enabled"; static const char _disabled[] = "disabled"; @@ -671,7 +644,6 @@ static const struct attribute_group pm_qos_latency_tolerance_attr_group = { static struct attribute *pm_qos_flags_attrs[] = { &dev_attr_pm_qos_no_power_off.attr, - &dev_attr_pm_qos_remote_wakeup.attr, NULL, }; static const struct attribute_group pm_qos_flags_attr_group = { diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h index 032b55909145..51f0d7e0b15f 100644 --- a/include/linux/pm_qos.h +++ b/include/linux/pm_qos.h @@ -39,7 +39,6 @@ enum pm_qos_flags_status { #define PM_QOS_LATENCY_ANY ((s32)(~(__u32)0 >> 1)) #define PM_QOS_FLAG_NO_POWER_OFF (1 << 0) -#define PM_QOS_FLAG_REMOTE_WAKEUP (1 << 1) struct pm_qos_request { struct plist_node node; -- cgit v1.2.3 From 0759e80b84e34a84e7e46e2b1adb528c83d84a47 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 7 Nov 2017 11:33:49 +0100 Subject: PM / QoS: Fix device resume latency framework The special value of 0 for device resume latency PM QoS means "no restriction", but there are two problems with that. First, device resume latency PM QoS requests with 0 as the value are always put in front of requests with positive values in the priority lists used internally by the PM QoS framework, causing 0 to be chosen as an effective constraint value. However, that 0 is then interpreted as "no restriction" effectively overriding the other requests with specific restrictions which is incorrect. Second, the users of device resume latency PM QoS have no way to specify that *any* resume latency at all should be avoided, which is an artificial limitation in general. To address these issues, modify device resume latency PM QoS to use S32_MAX as the "no constraint" value and 0 as the "no latency at all" one and rework its users (the cpuidle menu governor, the genpd QoS governor and the runtime PM framework) to follow these changes. Also add a special "n/a" value to the corresponding user space I/F to allow user space to indicate that it cannot accept any resume latencies at all for the given device. Fixes: 85dc0b8a4019 (PM / QoS: Make it possible to expose PM QoS latency constraints) Link: https://bugzilla.kernel.org/show_bug.cgi?id=197323 Reported-by: Reinette Chatre Signed-off-by: Rafael J. Wysocki Tested-by: Reinette Chatre Tested-by: Geert Uytterhoeven Tested-by: Tero Kristo Reviewed-by: Ramesh Thomas --- Documentation/ABI/testing/sysfs-devices-power | 4 ++- drivers/base/cpu.c | 3 +- drivers/base/power/domain.c | 2 +- drivers/base/power/domain_governor.c | 40 +++++++++++---------------- drivers/base/power/qos.c | 5 +++- drivers/base/power/runtime.c | 2 +- drivers/base/power/sysfs.c | 25 ++++++++++++++--- drivers/cpuidle/governors/menu.c | 4 +-- include/linux/pm_qos.h | 26 +++++++++++------ 9 files changed, 68 insertions(+), 43 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-devices-power b/Documentation/ABI/testing/sysfs-devices-power index f4b24c327665..80a00f7b6667 100644 --- a/Documentation/ABI/testing/sysfs-devices-power +++ b/Documentation/ABI/testing/sysfs-devices-power @@ -211,7 +211,9 @@ Description: device, after it has been suspended at run time, from a resume request to the moment the device will be ready to process I/O, in microseconds. If it is equal to 0, however, this means that - the PM QoS resume latency may be arbitrary. + the PM QoS resume latency may be arbitrary and the special value + "n/a" means that user space cannot accept any resume latency at + all for the given device. Not all drivers support this attribute. If it isn't supported, it is not present. diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index 321cd7b4d817..227bac5f1191 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -377,7 +377,8 @@ int register_cpu(struct cpu *cpu, int num) per_cpu(cpu_sys_devices, num) = &cpu->dev; register_cpu_under_node(num, cpu_to_node(num)); - dev_pm_qos_expose_latency_limit(&cpu->dev, 0); + dev_pm_qos_expose_latency_limit(&cpu->dev, + PM_QOS_RESUME_LATENCY_NO_CONSTRAINT); return 0; } diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 679c79545e42..24e39ce27bd8 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -1326,7 +1326,7 @@ static struct generic_pm_domain_data *genpd_alloc_dev_data(struct device *dev, gpd_data->base.dev = dev; gpd_data->td.constraint_changed = true; - gpd_data->td.effective_constraint_ns = 0; + gpd_data->td.effective_constraint_ns = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT_NS; gpd_data->nb.notifier_call = genpd_dev_pm_qos_notifier; spin_lock_irq(&dev->power.lock); diff --git a/drivers/base/power/domain_governor.c b/drivers/base/power/domain_governor.c index e4cca8adab32..99896fbf18e4 100644 --- a/drivers/base/power/domain_governor.c +++ b/drivers/base/power/domain_governor.c @@ -33,15 +33,10 @@ static int dev_update_qos_constraint(struct device *dev, void *data) * known at this point anyway). */ constraint_ns = dev_pm_qos_read_value(dev); - if (constraint_ns > 0) - constraint_ns *= NSEC_PER_USEC; + constraint_ns *= NSEC_PER_USEC; } - /* 0 means "no constraint" */ - if (constraint_ns == 0) - return 0; - - if (constraint_ns < *constraint_ns_p || *constraint_ns_p == 0) + if (constraint_ns < *constraint_ns_p) *constraint_ns_p = constraint_ns; return 0; @@ -69,12 +64,12 @@ static bool default_suspend_ok(struct device *dev) } td->constraint_changed = false; td->cached_suspend_ok = false; - td->effective_constraint_ns = -1; + td->effective_constraint_ns = 0; constraint_ns = __dev_pm_qos_read_value(dev); spin_unlock_irqrestore(&dev->power.lock, flags); - if (constraint_ns < 0) + if (constraint_ns == 0) return false; constraint_ns *= NSEC_PER_USEC; @@ -87,25 +82,25 @@ static bool default_suspend_ok(struct device *dev) device_for_each_child(dev, &constraint_ns, dev_update_qos_constraint); - if (constraint_ns == 0) { + if (constraint_ns == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT_NS) { /* "No restriction", so the device is allowed to suspend. */ - td->effective_constraint_ns = 0; + td->effective_constraint_ns = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT_NS; td->cached_suspend_ok = true; - } else if (constraint_ns < 0) { + } else if (constraint_ns == 0) { /* * This triggers if one of the children that don't belong to a - * domain has a negative PM QoS constraint and it's better not - * to suspend then. effective_constraint_ns is negative already - * and cached_suspend_ok is false, so bail out. + * domain has a zero PM QoS constraint and it's better not to + * suspend then. effective_constraint_ns is zero already and + * cached_suspend_ok is false, so bail out. */ return false; } else { constraint_ns -= td->suspend_latency_ns + td->resume_latency_ns; /* - * effective_constraint_ns is negative already and - * cached_suspend_ok is false, so if the computed value is not - * positive, return right away. + * effective_constraint_ns is zero already and cached_suspend_ok + * is false, so if the computed value is not positive, return + * right away. */ if (constraint_ns <= 0) return false; @@ -174,13 +169,10 @@ static bool __default_power_down_ok(struct dev_pm_domain *pd, td = &to_gpd_data(pdd)->td; constraint_ns = td->effective_constraint_ns; /* - * Negative values mean "no suspend at all" and this runs only - * when all devices in the domain are suspended, so it must be - * 0 at least. - * - * 0 means "no constraint" + * Zero means "no suspend at all" and this runs only when all + * devices in the domain are suspended, so it must be positive. */ - if (constraint_ns == 0) + if (constraint_ns == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT_NS) continue; if (constraint_ns <= off_on_time_ns) diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c index 277d43a83f53..3382542b39b7 100644 --- a/drivers/base/power/qos.c +++ b/drivers/base/power/qos.c @@ -139,6 +139,9 @@ static int apply_constraint(struct dev_pm_qos_request *req, switch(req->type) { case DEV_PM_QOS_RESUME_LATENCY: + if (WARN_ON(action != PM_QOS_REMOVE_REQ && value < 0)) + value = 0; + ret = pm_qos_update_target(&qos->resume_latency, &req->data.pnode, action, value); break; @@ -189,7 +192,7 @@ static int dev_pm_qos_constraints_allocate(struct device *dev) plist_head_init(&c->list); c->target_value = PM_QOS_RESUME_LATENCY_DEFAULT_VALUE; c->default_value = PM_QOS_RESUME_LATENCY_DEFAULT_VALUE; - c->no_constraint_value = PM_QOS_RESUME_LATENCY_DEFAULT_VALUE; + c->no_constraint_value = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT; c->type = PM_QOS_MIN; c->notifiers = n; diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 7bcf80fa9ada..13e015905543 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -253,7 +253,7 @@ static int rpm_check_suspend_allowed(struct device *dev) || (dev->power.request_pending && dev->power.request == RPM_REQ_RESUME)) retval = -EAGAIN; - else if (__dev_pm_qos_read_value(dev) < 0) + else if (__dev_pm_qos_read_value(dev) == 0) retval = -EPERM; else if (dev->power.runtime_status == RPM_SUSPENDED) retval = 1; diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c index 29bf28fef136..e153e28b1857 100644 --- a/drivers/base/power/sysfs.c +++ b/drivers/base/power/sysfs.c @@ -218,7 +218,14 @@ static ssize_t pm_qos_resume_latency_show(struct device *dev, struct device_attribute *attr, char *buf) { - return sprintf(buf, "%d\n", dev_pm_qos_requested_resume_latency(dev)); + s32 value = dev_pm_qos_requested_resume_latency(dev); + + if (value == 0) + return sprintf(buf, "n/a\n"); + else if (value == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT) + value = 0; + + return sprintf(buf, "%d\n", value); } static ssize_t pm_qos_resume_latency_store(struct device *dev, @@ -228,11 +235,21 @@ static ssize_t pm_qos_resume_latency_store(struct device *dev, s32 value; int ret; - if (kstrtos32(buf, 0, &value)) - return -EINVAL; + if (!kstrtos32(buf, 0, &value)) { + /* + * Prevent users from writing negative or "no constraint" values + * directly. + */ + if (value < 0 || value == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT) + return -EINVAL; - if (value < 0) + if (value == 0) + value = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT; + } else if (!strcmp(buf, "n/a") || !strcmp(buf, "n/a\n")) { + value = 0; + } else { return -EINVAL; + } ret = dev_pm_qos_update_request(dev->power.qos->resume_latency_req, value); diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c index 48eaf2879228..aa390404e85f 100644 --- a/drivers/cpuidle/governors/menu.c +++ b/drivers/cpuidle/governors/menu.c @@ -298,8 +298,8 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) data->needs_update = 0; } - /* resume_latency is 0 means no restriction */ - if (resume_latency && resume_latency < latency_req) + if (resume_latency < latency_req && + resume_latency != PM_QOS_RESUME_LATENCY_NO_CONSTRAINT) latency_req = resume_latency; /* Special case when user has set very strict latency requirement */ diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h index 51f0d7e0b15f..2a3b36da61b1 100644 --- a/include/linux/pm_qos.h +++ b/include/linux/pm_qos.h @@ -27,16 +27,19 @@ enum pm_qos_flags_status { PM_QOS_FLAGS_ALL, }; -#define PM_QOS_DEFAULT_VALUE -1 +#define PM_QOS_DEFAULT_VALUE (-1) +#define PM_QOS_LATENCY_ANY S32_MAX +#define PM_QOS_LATENCY_ANY_NS ((s64)PM_QOS_LATENCY_ANY * NSEC_PER_USEC) #define PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE (2000 * USEC_PER_SEC) #define PM_QOS_NETWORK_LAT_DEFAULT_VALUE (2000 * USEC_PER_SEC) #define PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE 0 #define PM_QOS_MEMORY_BANDWIDTH_DEFAULT_VALUE 0 -#define PM_QOS_RESUME_LATENCY_DEFAULT_VALUE 0 +#define PM_QOS_RESUME_LATENCY_DEFAULT_VALUE PM_QOS_LATENCY_ANY +#define PM_QOS_RESUME_LATENCY_NO_CONSTRAINT PM_QOS_LATENCY_ANY +#define PM_QOS_RESUME_LATENCY_NO_CONSTRAINT_NS PM_QOS_LATENCY_ANY_NS #define PM_QOS_LATENCY_TOLERANCE_DEFAULT_VALUE 0 #define PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT (-1) -#define PM_QOS_LATENCY_ANY ((s32)(~(__u32)0 >> 1)) #define PM_QOS_FLAG_NO_POWER_OFF (1 << 0) @@ -173,7 +176,8 @@ static inline s32 dev_pm_qos_requested_flags(struct device *dev) static inline s32 dev_pm_qos_raw_read_value(struct device *dev) { return IS_ERR_OR_NULL(dev->power.qos) ? - 0 : pm_qos_read_value(&dev->power.qos->resume_latency); + PM_QOS_RESUME_LATENCY_NO_CONSTRAINT : + pm_qos_read_value(&dev->power.qos->resume_latency); } #else static inline enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev, @@ -183,9 +187,9 @@ static inline enum pm_qos_flags_status dev_pm_qos_flags(struct device *dev, s32 mask) { return PM_QOS_FLAGS_UNDEFINED; } static inline s32 __dev_pm_qos_read_value(struct device *dev) - { return 0; } + { return PM_QOS_RESUME_LATENCY_NO_CONSTRAINT; } static inline s32 dev_pm_qos_read_value(struct device *dev) - { return 0; } + { return PM_QOS_RESUME_LATENCY_NO_CONSTRAINT; } static inline int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req, enum dev_pm_qos_req_type type, @@ -231,9 +235,15 @@ static inline int dev_pm_qos_expose_latency_tolerance(struct device *dev) { return 0; } static inline void dev_pm_qos_hide_latency_tolerance(struct device *dev) {} -static inline s32 dev_pm_qos_requested_resume_latency(struct device *dev) { return 0; } +static inline s32 dev_pm_qos_requested_resume_latency(struct device *dev) +{ + return PM_QOS_RESUME_LATENCY_NO_CONSTRAINT; +} static inline s32 dev_pm_qos_requested_flags(struct device *dev) { return 0; } -static inline s32 dev_pm_qos_raw_read_value(struct device *dev) { return 0; } +static inline s32 dev_pm_qos_raw_read_value(struct device *dev) +{ + return PM_QOS_RESUME_LATENCY_NO_CONSTRAINT; +} #endif #endif -- cgit v1.2.3