From 13b2c4a0c3b1cd37ee6bcfbb5b6e2b94e9a75364 Mon Sep 17 00:00:00 2001 From: Mika Westerberg Date: Mon, 27 Jul 2015 18:03:56 +0300 Subject: PM / QoS: Make it possible to expose device latency tolerance to userspace Typically when a device is created the bus core it belongs to (for example PCI) does not know if the device supports things like latency tolerance. This is left to the driver that binds to the device in question. However, at that time the device has already been created and there is no way to set its dev->power.set_latency_tolerance anymore. So follow what has been done for other PM QoS attributes as well and allow drivers to expose and hide latency tolerance from userspace, if the device supports it. Acked-by: Rafael J. Wysocki Signed-off-by: Mika Westerberg Signed-off-by: Andy Shevchenko Signed-off-by: Lee Jones --- drivers/base/power/qos.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) (limited to 'drivers/base/power/qos.c') diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c index e56d538d039e..7f3646e459cb 100644 --- a/drivers/base/power/qos.c +++ b/drivers/base/power/qos.c @@ -883,3 +883,40 @@ int dev_pm_qos_update_user_latency_tolerance(struct device *dev, s32 val) mutex_unlock(&dev_pm_qos_mtx); return ret; } + +/** + * dev_pm_qos_expose_latency_tolerance - Expose latency tolerance to userspace + * @dev: Device whose latency tolerance to expose + */ +int dev_pm_qos_expose_latency_tolerance(struct device *dev) +{ + int ret; + + if (!dev->power.set_latency_tolerance) + return -EINVAL; + + mutex_lock(&dev_pm_qos_sysfs_mtx); + ret = pm_qos_sysfs_add_latency_tolerance(dev); + mutex_unlock(&dev_pm_qos_sysfs_mtx); + + return ret; +} +EXPORT_SYMBOL_GPL(dev_pm_qos_expose_latency_tolerance); + +/** + * dev_pm_qos_hide_latency_tolerance - Hide latency tolerance from userspace + * @dev: Device whose latency tolerance to hide + */ +void dev_pm_qos_hide_latency_tolerance(struct device *dev) +{ + mutex_lock(&dev_pm_qos_sysfs_mtx); + pm_qos_sysfs_remove_latency_tolerance(dev); + mutex_unlock(&dev_pm_qos_sysfs_mtx); + + /* Remove the request from user space now */ + pm_runtime_get_sync(dev); + dev_pm_qos_update_user_latency_tolerance(dev, + PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT); + pm_runtime_put(dev); +} +EXPORT_SYMBOL_GPL(dev_pm_qos_hide_latency_tolerance); -- cgit v1.2.3