From c4772d192c70b61d52262b0db76f7abd8aeb51c6 Mon Sep 17 00:00:00 2001 From: MyungJoo Ham Date: Wed, 28 Mar 2012 23:31:24 +0200 Subject: PM / QoS: add pm_qos_update_request_timeout() API The new API, pm_qos_update_request_timeout() is to provide a timeout with pm_qos_update_request. For example, pm_qos_update_request_timeout(req, 100, 1000), means that QoS request on req with value 100 will be active for 1000 microseconds. After 1000 microseconds, the QoS request thru req is reset. If there were another pm_qos_update_request(req, x) during the 1000 us, this new request with value x will override as this is another request on the same req handle. A new request on the same req handle will always override the previous request whether it is the conventional request or it is the new timeout request. Signed-off-by: MyungJoo Ham Signed-off-by: Kyungmin Park Acked-by: Mark Gross Signed-off-by: Rafael J. Wysocki --- include/linux/pm_qos.h | 4 ++++ kernel/power/qos.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 54 insertions(+) diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h index 2e9191a712f3..233149cb19f4 100644 --- a/include/linux/pm_qos.h +++ b/include/linux/pm_qos.h @@ -8,6 +8,7 @@ #include #include #include +#include enum { PM_QOS_RESERVED = 0, @@ -29,6 +30,7 @@ enum { struct pm_qos_request { struct plist_node node; int pm_qos_class; + struct delayed_work work; /* for pm_qos_update_request_timeout */ }; struct dev_pm_qos_request { @@ -73,6 +75,8 @@ void pm_qos_add_request(struct pm_qos_request *req, int pm_qos_class, s32 value); void pm_qos_update_request(struct pm_qos_request *req, s32 new_value); +void pm_qos_update_request_timeout(struct pm_qos_request *req, + s32 new_value, unsigned long timeout_us); void pm_qos_remove_request(struct pm_qos_request *req); int pm_qos_request(int pm_qos_class); diff --git a/kernel/power/qos.c b/kernel/power/qos.c index d6d6dbd1ecc0..6a031e684026 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -229,6 +229,21 @@ int pm_qos_request_active(struct pm_qos_request *req) } EXPORT_SYMBOL_GPL(pm_qos_request_active); +/** + * pm_qos_work_fn - the timeout handler of pm_qos_update_request_timeout + * @work: work struct for the delayed work (timeout) + * + * This cancels the timeout request by falling back to the default at timeout. + */ +static void pm_qos_work_fn(struct work_struct *work) +{ + struct pm_qos_request *req = container_of(to_delayed_work(work), + struct pm_qos_request, + work); + + pm_qos_update_request(req, PM_QOS_DEFAULT_VALUE); +} + /** * pm_qos_add_request - inserts new qos request into the list * @req: pointer to a preallocated handle @@ -253,6 +268,7 @@ void pm_qos_add_request(struct pm_qos_request *req, return; } req->pm_qos_class = pm_qos_class; + INIT_DELAYED_WORK(&req->work, pm_qos_work_fn); pm_qos_update_target(pm_qos_array[pm_qos_class]->constraints, &req->node, PM_QOS_ADD_REQ, value); } @@ -279,6 +295,9 @@ void pm_qos_update_request(struct pm_qos_request *req, return; } + if (delayed_work_pending(&req->work)) + cancel_delayed_work_sync(&req->work); + if (new_value != req->node.prio) pm_qos_update_target( pm_qos_array[req->pm_qos_class]->constraints, @@ -286,6 +305,34 @@ void pm_qos_update_request(struct pm_qos_request *req, } EXPORT_SYMBOL_GPL(pm_qos_update_request); +/** + * pm_qos_update_request_timeout - modifies an existing qos request temporarily. + * @req : handle to list element holding a pm_qos request to use + * @new_value: defines the temporal qos request + * @timeout_us: the effective duration of this qos request in usecs. + * + * After timeout_us, this qos request is cancelled automatically. + */ +void pm_qos_update_request_timeout(struct pm_qos_request *req, s32 new_value, + unsigned long timeout_us) +{ + if (!req) + return; + if (WARN(!pm_qos_request_active(req), + "%s called for unknown object.", __func__)) + return; + + if (delayed_work_pending(&req->work)) + cancel_delayed_work_sync(&req->work); + + if (new_value != req->node.prio) + pm_qos_update_target( + pm_qos_array[req->pm_qos_class]->constraints, + &req->node, PM_QOS_UPDATE_REQ, new_value); + + schedule_delayed_work(&req->work, usecs_to_jiffies(timeout_us)); +} + /** * pm_qos_remove_request - modifies an existing qos request * @req: handle to request list element @@ -305,6 +352,9 @@ void pm_qos_remove_request(struct pm_qos_request *req) return; } + if (delayed_work_pending(&req->work)) + cancel_delayed_work_sync(&req->work); + pm_qos_update_target(pm_qos_array[req->pm_qos_class]->constraints, &req->node, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE); -- cgit v1.2.3