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-rw-r--r--Documentation/ABI/testing/sysfs-devices-power4
-rw-r--r--drivers/base/cpu.c3
-rw-r--r--drivers/base/power/domain_governor.c53
-rw-r--r--drivers/base/power/qos.c2
-rw-r--r--drivers/base/power/runtime.c2
-rw-r--r--drivers/base/power/sysfs.c25
-rw-r--r--drivers/cpuidle/governors/menu.c4
-rw-r--r--include/linux/pm_qos.h5
8 files changed, 63 insertions, 35 deletions
diff --git a/Documentation/ABI/testing/sysfs-devices-power b/Documentation/ABI/testing/sysfs-devices-power
index 676fdf5f2a99..5cbb6f038615 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_governor.c b/drivers/base/power/domain_governor.c
index 281f949c5ffe..51751cc8c9e6 100644
--- a/drivers/base/power/domain_governor.c
+++ b/drivers/base/power/domain_governor.c
@@ -14,23 +14,20 @@
static int dev_update_qos_constraint(struct device *dev, void *data)
{
s64 *constraint_ns_p = data;
- s32 constraint_ns = -1;
+ s64 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);
- constraint_ns *= NSEC_PER_USEC;
- }
- if (constraint_ns == 0)
+
+ if (constraint_ns == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT)
return 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 *= NSEC_PER_USEC;
+
+ if (constraint_ns < *constraint_ns_p || *constraint_ns_p < 0)
*constraint_ns_p = constraint_ns;
return 0;
@@ -63,10 +60,14 @@ 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;
- constraint_ns *= NSEC_PER_USEC;
+ if (constraint_ns == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT)
+ constraint_ns = -1;
+ else
+ 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
@@ -76,14 +77,19 @@ static bool default_suspend_ok(struct device *dev)
device_for_each_child(dev, &constraint_ns,
dev_update_qos_constraint);
- if (constraint_ns > 0) {
- constraint_ns -= td->suspend_latency_ns +
- td->resume_latency_ns;
- if (constraint_ns == 0)
- return false;
+ 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;
+ }
}
- 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
@@ -145,13 +151,14 @@ 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);
- constraint_ns *= NSEC_PER_USEC;
- }
- if (constraint_ns == 0)
+
+ if (constraint_ns == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT)
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 277d43a83f53..7d29286d9313 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_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 156ab57bca77..632077f05c57 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 032b55909145..6737a8c9e8c6 100644
--- a/include/linux/pm_qos.h
+++ b/include/linux/pm_qos.h
@@ -27,16 +27,17 @@ 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_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)
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-22 06:22:35 +0000