From d5919dcc349d2a16d805ef8096d36e4f519e42ae Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 31 Oct 2017 18:26:15 +0100 Subject: [PATCH] Revert "PM / QoS: Fix device resume latency PM QoS" This reverts commit 0cc2b4e5a020 (PM / QoS: Fix device resume latency PM QoS) as it introduced regressions on multiple systems and the fix-up in commit 2a9a86d5c813 (PM / QoS: Fix default runtime_pm device resume latency) does not address all of them. The original problem that commit 0cc2b4e5a020 was attempting to fix will be addressed later. Fixes: 0cc2b4e5a020 (PM / QoS: Fix device resume latency PM QoS) Reported-by: Geert Uytterhoeven Signed-off-by: Rafael J. Wysocki --- Documentation/ABI/testing/sysfs-devices-power | 4 +- drivers/base/cpu.c | 3 +- drivers/base/power/domain_governor.c | 53 ++++++++++++--------------- drivers/base/power/qos.c | 2 +- drivers/base/power/runtime.c | 2 +- drivers/base/power/sysfs.c | 25 ++----------- drivers/cpuidle/governors/menu.c | 4 +- include/linux/pm_qos.h | 5 +-- 8 files changed, 35 insertions(+), 63 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-devices-power b/Documentation/ABI/testing/sysfs-devices-power index 5cbb6f0..676fdf5 100644 --- a/Documentation/ABI/testing/sysfs-devices-power +++ b/Documentation/ABI/testing/sysfs-devices-power @@ -211,9 +211,7 @@ 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 and the special value - "n/a" means that user space cannot accept any resume latency at - all for the given device. + the PM QoS resume latency may be arbitrary. 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 227bac5..321cd7b 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -377,8 +377,7 @@ 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, - PM_QOS_RESUME_LATENCY_NO_CONSTRAINT); + dev_pm_qos_expose_latency_limit(&cpu->dev, 0); return 0; } diff --git a/drivers/base/power/domain_governor.c b/drivers/base/power/domain_governor.c index 51751cc..281f949 100644 --- a/drivers/base/power/domain_governor.c +++ b/drivers/base/power/domain_governor.c @@ -14,20 +14,23 @@ static int dev_update_qos_constraint(struct device *dev, void *data) { s64 *constraint_ns_p = data; - s64 constraint_ns = -1; + s32 constraint_ns = -1; if (dev->power.subsys_data && dev->power.subsys_data->domain_data) constraint_ns = dev_gpd_data(dev)->td.effective_constraint_ns; - if (constraint_ns < 0) + if (constraint_ns < 0) { constraint_ns = dev_pm_qos_read_value(dev); - - if (constraint_ns == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT) + constraint_ns *= NSEC_PER_USEC; + } + if (constraint_ns == 0) return 0; - constraint_ns *= NSEC_PER_USEC; - - if (constraint_ns < *constraint_ns_p || *constraint_ns_p < 0) + /* + * constraint_ns cannot be negative here, because the device has been + * suspended. + */ + if (constraint_ns < *constraint_ns_p || *constraint_ns_p == 0) *constraint_ns_p = constraint_ns; return 0; @@ -60,14 +63,10 @@ static bool default_suspend_ok(struct device *dev) spin_unlock_irqrestore(&dev->power.lock, flags); - if (constraint_ns == 0) + if (constraint_ns < 0) return false; - if (constraint_ns == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT) - constraint_ns = -1; - else - constraint_ns *= NSEC_PER_USEC; - + constraint_ns *= NSEC_PER_USEC; /* * We can walk the children without any additional locking, because * they all have been suspended at this point and their @@ -77,19 +76,14 @@ static bool default_suspend_ok(struct device *dev) device_for_each_child(dev, &constraint_ns, dev_update_qos_constraint); - if (constraint_ns < 0) { - /* The children have no constraints. */ - td->effective_constraint_ns = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT; - td->cached_suspend_ok = true; - } else { - constraint_ns -= td->suspend_latency_ns + td->resume_latency_ns; - if (constraint_ns > 0) { - td->effective_constraint_ns = constraint_ns; - td->cached_suspend_ok = true; - } else { - td->effective_constraint_ns = 0; - } + if (constraint_ns > 0) { + constraint_ns -= td->suspend_latency_ns + + td->resume_latency_ns; + if (constraint_ns == 0) + return false; } + td->effective_constraint_ns = constraint_ns; + td->cached_suspend_ok = constraint_ns >= 0; /* * The children have been suspended already, so we don't need to take @@ -151,14 +145,13 @@ static bool __default_power_down_ok(struct dev_pm_domain *pd, td = &to_gpd_data(pdd)->td; constraint_ns = td->effective_constraint_ns; /* default_suspend_ok() need not be called before us. */ - if (constraint_ns < 0) + if (constraint_ns < 0) { constraint_ns = dev_pm_qos_read_value(pdd->dev); - - if (constraint_ns == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT) + constraint_ns *= NSEC_PER_USEC; + } + if (constraint_ns == 0) continue; - constraint_ns *= NSEC_PER_USEC; - /* * constraint_ns cannot be negative here, because the device has * been suspended. diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c index 7d29286..277d43a 100644 --- a/drivers/base/power/qos.c +++ b/drivers/base/power/qos.c @@ -189,7 +189,7 @@ 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_NO_CONSTRAINT; + c->no_constraint_value = PM_QOS_RESUME_LATENCY_DEFAULT_VALUE; c->type = PM_QOS_MIN; c->notifiers = n; diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 13e0159..7bcf80f 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 632077f..156ab57 100644 --- a/drivers/base/power/sysfs.c +++ b/drivers/base/power/sysfs.c @@ -218,14 +218,7 @@ static ssize_t pm_qos_resume_latency_show(struct device *dev, struct device_attribute *attr, char *buf) { - 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); + return sprintf(buf, "%d\n", dev_pm_qos_requested_resume_latency(dev)); } static ssize_t pm_qos_resume_latency_store(struct device *dev, @@ -235,21 +228,11 @@ static ssize_t pm_qos_resume_latency_store(struct device *dev, s32 value; int ret; - 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 (kstrtos32(buf, 0, &value)) + return -EINVAL; - if (value == 0) - value = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT; - } else if (!strcmp(buf, "n/a") || !strcmp(buf, "n/a\n")) { - value = 0; - } else { + if (value < 0) 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 aa39040..48eaf28 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; } - if (resume_latency < latency_req && - resume_latency != PM_QOS_RESUME_LATENCY_NO_CONSTRAINT) + /* resume_latency is 0 means no restriction */ + if (resume_latency && resume_latency < latency_req) 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 6737a8c..032b559 100644 --- a/include/linux/pm_qos.h +++ b/include/linux/pm_qos.h @@ -27,17 +27,16 @@ enum pm_qos_flags_status { PM_QOS_FLAGS_ALL, }; -#define PM_QOS_DEFAULT_VALUE (-1) -#define PM_QOS_LATENCY_ANY S32_MAX +#define PM_QOS_DEFAULT_VALUE -1 #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_NO_CONSTRAINT PM_QOS_LATENCY_ANY #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) #define PM_QOS_FLAG_REMOTE_WAKEUP (1 << 1) -- 2.7.4