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Message-Id: <1276097381-3982-1-git-send-email-florian@mickler.org>
Date: Wed, 9 Jun 2010 17:29:41 +0200
From: florian@...kler.org
To: pm list <linux-pm@...ts.linux-foundation.org>
Cc: james.bottomley@...e.de, markgross@...gnar.org,
mgross@...ux.intel.com, linville@...driver.com,
Florian Mickler <florian@...kler.org>,
Frederic Weisbecker <fweisbec@...il.com>,
Jonathan Corbet <corbet@....net>,
Thomas Gleixner <tglx@...utronix.de>,
linux-kernel@...r.kernel.org
Subject: [PATCH v4] pm_qos: make update_request non blocking
In order to allow drivers to use pm_qos_update_request from interrupt
context we call the notifiers via schedule_work().
Signed-off-by: Florian Mickler <florian@...kler.org>
---
Well, this would be the schedule_work() alternative.
kernel/pm_qos_params.c | 47 ++++++++++++++++++++++++++++++-----------------
1 files changed, 30 insertions(+), 17 deletions(-)
diff --git a/kernel/pm_qos_params.c b/kernel/pm_qos_params.c
index f42d3f7..296343a 100644
--- a/kernel/pm_qos_params.c
+++ b/kernel/pm_qos_params.c
@@ -40,6 +40,7 @@
#include <linux/string.h>
#include <linux/platform_device.h>
#include <linux/init.h>
+#include <linux/workqueue.h>
#include <linux/uaccess.h>
@@ -60,11 +61,13 @@ struct pm_qos_request_list {
static s32 max_compare(s32 v1, s32 v2);
static s32 min_compare(s32 v1, s32 v2);
+static void update_notify(struct work_struct *work);
struct pm_qos_object {
struct pm_qos_request_list requests;
struct blocking_notifier_head *notifiers;
struct miscdevice pm_qos_power_miscdev;
+ struct work_struct notify;
char *name;
s32 default_value;
atomic_t target_value;
@@ -72,10 +75,12 @@ struct pm_qos_object {
};
static struct pm_qos_object null_pm_qos;
+
static BLOCKING_NOTIFIER_HEAD(cpu_dma_lat_notifier);
static struct pm_qos_object cpu_dma_pm_qos = {
.requests = {LIST_HEAD_INIT(cpu_dma_pm_qos.requests.list)},
.notifiers = &cpu_dma_lat_notifier,
+ .notify = __WORK_INITIALIZER(cpu_dma_pm_qos.notify, update_notify),
.name = "cpu_dma_latency",
.default_value = 2000 * USEC_PER_SEC,
.target_value = ATOMIC_INIT(2000 * USEC_PER_SEC),
@@ -86,6 +91,7 @@ static BLOCKING_NOTIFIER_HEAD(network_lat_notifier);
static struct pm_qos_object network_lat_pm_qos = {
.requests = {LIST_HEAD_INIT(network_lat_pm_qos.requests.list)},
.notifiers = &network_lat_notifier,
+ .notify = __WORK_INITIALIZER(network_lat_pm_qos.notify, update_notify),
.name = "network_latency",
.default_value = 2000 * USEC_PER_SEC,
.target_value = ATOMIC_INIT(2000 * USEC_PER_SEC),
@@ -97,13 +103,14 @@ static BLOCKING_NOTIFIER_HEAD(network_throughput_notifier);
static struct pm_qos_object network_throughput_pm_qos = {
.requests = {LIST_HEAD_INIT(network_throughput_pm_qos.requests.list)},
.notifiers = &network_throughput_notifier,
+ .notify = __WORK_INITIALIZER(network_throughput_pm_qos.notify,
+ update_notify),
.name = "network_throughput",
.default_value = 0,
.target_value = ATOMIC_INIT(0),
.comparitor = max_compare
};
-
static struct pm_qos_object *pm_qos_array[] = {
&null_pm_qos,
&cpu_dma_pm_qos,
@@ -135,35 +142,40 @@ static s32 min_compare(s32 v1, s32 v2)
return min(v1, v2);
}
+static void update_notify(struct work_struct *work)
+{
+ struct pm_qos_object *obj =
+ container_of(work, struct pm_qos_object, notify);
+
+ s32 extreme_value = atomic_read(&obj->target_value);
+ blocking_notifier_call_chain(
+ obj->notifiers,
+ (unsigned long) extreme_value, NULL);
+}
static void update_target(int pm_qos_class)
{
s32 extreme_value;
struct pm_qos_request_list *node;
+ struct pm_qos_object *obj = pm_qos_array[pm_qos_class];
unsigned long flags;
int call_notifier = 0;
spin_lock_irqsave(&pm_qos_lock, flags);
- extreme_value = pm_qos_array[pm_qos_class]->default_value;
- list_for_each_entry(node,
- &pm_qos_array[pm_qos_class]->requests.list, list) {
- extreme_value = pm_qos_array[pm_qos_class]->comparitor(
- extreme_value, node->value);
- }
- if (atomic_read(&pm_qos_array[pm_qos_class]->target_value) !=
- extreme_value) {
+ extreme_value = obj->default_value;
+ list_for_each_entry(node, &obj->requests.list, list)
+ extreme_value = obj->comparitor(extreme_value, node->value);
+
+ if (atomic_read(&obj->target_value) != extreme_value) {
call_notifier = 1;
- atomic_set(&pm_qos_array[pm_qos_class]->target_value,
- extreme_value);
+ atomic_set(&obj->target_value, extreme_value);
pr_debug(KERN_ERR "new target for qos %d is %d\n", pm_qos_class,
- atomic_read(&pm_qos_array[pm_qos_class]->target_value));
+ atomic_read(&obj->target_value));
}
spin_unlock_irqrestore(&pm_qos_lock, flags);
if (call_notifier)
- blocking_notifier_call_chain(
- pm_qos_array[pm_qos_class]->notifiers,
- (unsigned long) extreme_value, NULL);
+ schedule_work(&obj->notify);
}
static int register_pm_qos_misc(struct pm_qos_object *qos)
@@ -301,7 +313,7 @@ EXPORT_SYMBOL_GPL(pm_qos_remove_request);
* @pm_qos_class: identifies which qos target changes should be notified.
* @notifier: notifier block managed by caller.
*
- * will register the notifier into a notification chain that gets called
+ * Will register the notifier into a notification chain that gets called
* upon changes to the pm_qos_class target value.
*/
int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier)
@@ -320,7 +332,7 @@ EXPORT_SYMBOL_GPL(pm_qos_add_notifier);
* @pm_qos_class: identifies which qos target changes are notified.
* @notifier: notifier block to be removed.
*
- * will remove the notifier from the notification chain that gets called
+ * Will remove the notifier from the notification chain that gets called
* upon changes to the pm_qos_class target value.
*/
int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier)
@@ -392,6 +404,7 @@ static int __init pm_qos_power_init(void)
{
int ret = 0;
+
ret = register_pm_qos_misc(&cpu_dma_pm_qos);
if (ret < 0) {
printk(KERN_ERR "pm_qos_param: cpu_dma_latency setup failed\n");
--
1.7.1
--
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