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Subject[PATCH 1/3] pm/qos: allow state control of qos class
Date
When power capping or thermal control is needed, CPU QOS latency cannot
be satisfied. This patch adds a state variable to indicate whether a QOS
class (including all constraint requests) should be ignored.

Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
---
include/linux/pm_qos.h | 10 +++++++++-
kernel/power/qos.c | 24 ++++++++++++++++++++++++
2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h
index 5a95013..648b50b 100644
--- a/include/linux/pm_qos.h
+++ b/include/linux/pm_qos.h
@@ -10,7 +10,7 @@
#include <linux/device.h>
#include <linux/workqueue.h>

-enum {
+enum pm_qos_class {
PM_QOS_RESERVED = 0,
PM_QOS_CPU_DMA_LATENCY,
PM_QOS_NETWORK_LATENCY,
@@ -20,6 +20,11 @@ enum {
PM_QOS_NUM_CLASSES,
};

+enum pm_qos_state {
+ PM_QOS_CONSTRAINT_AVAILABLE,
+ PM_QOS_CONSTRAINT_IGNORED,
+};
+
enum pm_qos_flags_status {
PM_QOS_FLAGS_UNDEFINED = -1,
PM_QOS_FLAGS_NONE,
@@ -77,6 +82,7 @@ struct pm_qos_constraints {
struct plist_head list;
s32 target_value; /* Do not change to 64 bit */
s32 default_value;
+ enum pm_qos_state state;
enum pm_qos_type type;
struct blocking_notifier_head *notifiers;
};
@@ -123,6 +129,8 @@ int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier);
int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier);
int pm_qos_request_active(struct pm_qos_request *req);
s32 pm_qos_read_value(struct pm_qos_constraints *c);
+void pm_qos_set_constraint_class_state(enum pm_qos_class class,
+ enum pm_qos_state state);

#ifdef CONFIG_PM
enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev, s32 mask);
diff --git a/kernel/power/qos.c b/kernel/power/qos.c
index 8dff9b4..cf475b0 100644
--- a/kernel/power/qos.c
+++ b/kernel/power/qos.c
@@ -146,6 +146,11 @@ static inline int pm_qos_get_value(struct pm_qos_constraints *c)

s32 pm_qos_read_value(struct pm_qos_constraints *c)
{
+ /* return invalid default value if constraints cannot be met, e.g.
+ * during idle injection.
+ */
+ if (c->state == PM_QOS_CONSTRAINT_IGNORED)
+ return PM_QOS_DEFAULT_VALUE;
return c->target_value;
}

@@ -353,6 +358,25 @@ void pm_qos_add_request(struct pm_qos_request *req,
}
EXPORT_SYMBOL_GPL(pm_qos_add_request);

+void pm_qos_set_constraint_class_state(enum pm_qos_class class,
+ enum pm_qos_state state)
+{
+ struct pm_qos_constraints *c = pm_qos_array[class]->constraints;
+ unsigned long curr_value;
+
+ if (c->state == state)
+ return;
+ curr_value = (state == PM_QOS_CONSTRAINT_IGNORED) ?
+ PM_QOS_DEFAULT_VALUE : c->target_value;
+ c->state = state;
+
+ /* notify existing QOS requests change */
+ blocking_notifier_call_chain(c->notifiers,
+ curr_value,
+ NULL);
+}
+EXPORT_SYMBOL_GPL(pm_qos_set_constraint_class_state);
+
/**
* pm_qos_update_request - modifies an existing qos request
* @req : handle to list element holding a pm_qos request to use
--
1.8.1.2


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