[RFC/RFT][PATCH 5/5] PM / QoS: Add type to dev_pm_qos_add_ancestor_request() arguments

From: Rafael J. Wysocki
Date: Fri Jan 17 2014 - 09:38:22 EST


From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

Rework dev_pm_qos_add_ancestor_request() so that device PM QoS type
is passed to it as the third argument and make it support the
DEV_PM_QOS_LATENCY_TOLERANCE device PM QoS type (in addition to
DEV_PM_QOS_RESUME_LATENCY).

That will allow the drivers of devices without latency tolerance
hardware support to use their ancestors having it as proxies for
their latency tolerance requirements.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
Documentation/power/pm_qos_interface.txt | 6 ++++--
drivers/base/power/qos.c | 22 +++++++++++++++++-----
drivers/input/touchscreen/st1232.c | 3 ++-
include/linux/pm_qos.h | 7 +++++--
4 files changed, 28 insertions(+), 10 deletions(-)

Index: linux-pm/include/linux/pm_qos.h
===================================================================
--- linux-pm.orig/include/linux/pm_qos.h
+++ linux-pm/include/linux/pm_qos.h
@@ -148,7 +148,8 @@ int dev_pm_qos_remove_global_notifier(st
void dev_pm_qos_constraints_init(struct device *dev);
void dev_pm_qos_constraints_destroy(struct device *dev);
int dev_pm_qos_add_ancestor_request(struct device *dev,
- struct dev_pm_qos_request *req, s32 value);
+ struct dev_pm_qos_request *req,
+ enum dev_pm_qos_req_type type, s32 value);
#else
static inline enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev,
s32 mask)
@@ -191,7 +192,9 @@ static inline void dev_pm_qos_constraint
dev->power.power_state = PMSG_INVALID;
}
static inline int dev_pm_qos_add_ancestor_request(struct device *dev,
- struct dev_pm_qos_request *req, s32 value)
+ struct dev_pm_qos_request *req,
+ enum dev_pm_qos_req_type type,
+ s32 value)
{ return 0; }
#endif

Index: linux-pm/drivers/base/power/qos.c
===================================================================
--- linux-pm.orig/drivers/base/power/qos.c
+++ linux-pm/drivers/base/power/qos.c
@@ -558,20 +558,32 @@ EXPORT_SYMBOL_GPL(dev_pm_qos_remove_glob
* dev_pm_qos_add_ancestor_request - Add PM QoS request for device's ancestor.
* @dev: Device whose ancestor to add the request for.
* @req: Pointer to the preallocated handle.
+ * @type: Type of the request.
* @value: Constraint latency value.
*/
int dev_pm_qos_add_ancestor_request(struct device *dev,
- struct dev_pm_qos_request *req, s32 value)
+ struct dev_pm_qos_request *req,
+ enum dev_pm_qos_req_type type, s32 value)
{
struct device *ancestor = dev->parent;
int ret = -ENODEV;

- while (ancestor && !ancestor->power.ignore_children)
- ancestor = ancestor->parent;
+ switch (type) {
+ case DEV_PM_QOS_RESUME_LATENCY:
+ while (ancestor && !ancestor->power.ignore_children)
+ ancestor = ancestor->parent;

+ break;
+ case DEV_PM_QOS_LATENCY_TOLERANCE:
+ while (ancestor && !ancestor->power.set_latency_tolerance)
+ ancestor = ancestor->parent;
+
+ break;
+ default:
+ ancestor = NULL;
+ }
if (ancestor)
- ret = dev_pm_qos_add_request(ancestor, req,
- DEV_PM_QOS_RESUME_LATENCY, value);
+ ret = dev_pm_qos_add_request(ancestor, req, type, value);

if (ret < 0)
req->dev = NULL;
Index: linux-pm/Documentation/power/pm_qos_interface.txt
===================================================================
--- linux-pm.orig/Documentation/power/pm_qos_interface.txt
+++ linux-pm/Documentation/power/pm_qos_interface.txt
@@ -134,9 +134,11 @@ The meaning of the return values is as f
PM_QOS_FLAGS_UNDEFINED: The device's PM QoS structure has not been
initialized or the list of requests is empty.

-int dev_pm_qos_add_ancestor_request(dev, handle, value)
+int dev_pm_qos_add_ancestor_request(dev, handle, type, value)
Add a PM QoS request for the first direct ancestor of the given device whose
-power.ignore_children flag is unset.
+power.ignore_children flag is unset (for DEV_PM_QOS_RESUME_LATENCY requests)
+or whose power.set_latency_tolerance callback pointer is not NULL (for
+DEV_PM_QOS_LATENCY_TOLERANCE requests).

int dev_pm_qos_expose_latency_limit(device, value)
Add a request to the device's PM QoS list of resume latency constraints and
Index: linux-pm/drivers/input/touchscreen/st1232.c
===================================================================
--- linux-pm.orig/drivers/input/touchscreen/st1232.c
+++ linux-pm/drivers/input/touchscreen/st1232.c
@@ -134,7 +134,8 @@ static irqreturn_t st1232_ts_irq_handler
} else if (!ts->low_latency_req.dev) {
/* First contact, request 100 us latency. */
dev_pm_qos_add_ancestor_request(&ts->client->dev,
- &ts->low_latency_req, 100);
+ &ts->low_latency_req,
+ DEV_PM_QOS_RESUME_LATENCY, 100);
}

/* SYN_REPORT */

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