On 09/29/2012 05:55 AM, Rafael J. Wysocki wrote:
> Define two device PM QoS flags, PM_QOS_FLAG_NO_POWER_OFF
> and PM_QOS_FLAG_REMOTE_WAKEUP, and introduce routines
> dev_pm_qos_expose_flags() and dev_pm_qos_hide_flags() allowing the
> caller to expose those two flags to user space or to hide them
> from it, respectively.
>
> After the flags have been exposed, user space will see two
> additional sysfs attributes, pm_qos_no_power_off and
> pm_qos_remote_wakeup, under the device's /sys/devices/.../power/
> directory. Then, writing 1 to one of them will update the
> PM QoS flags request owned by user space so that the corresponding
> flag is requested to be set. In turn, writing 0 to one of them
> will cause the corresponding flag in the user space's request to
> be cleared (however, the owners of the other PM QoS flags requests
> for the same device may still request the flag to be set and it
> may be effectively set even if user space doesn't request that).
>
> Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
> ---
> Documentation/ABI/testing/sysfs-devices-power | 31 ++++
> drivers/base/power/power.h | 6
> drivers/base/power/qos.c | 169 ++++++++++++++++++++------
> drivers/base/power/sysfs.c | 95 +++++++++++++-
> include/linux/pm.h | 1
> include/linux/pm_qos.h | 26 ++++
> 6 files changed, 280 insertions(+), 48 deletions(-)
>
> Index: linux/drivers/base/power/qos.c
> ===================================================================
> --- linux.orig/drivers/base/power/qos.c
> +++ linux/drivers/base/power/qos.c
> @@ -40,6 +40,7 @@
> #include <linux/device.h>
> #include <linux/mutex.h>
> #include <linux/export.h>
> +#include <linux/pm_runtime.h>
>
> #include "power.h"
>
> @@ -322,6 +323,38 @@ int dev_pm_qos_add_request(struct device
> EXPORT_SYMBOL_GPL(dev_pm_qos_add_request);
>
> /**
> + * __dev_pm_qos_update_request - Modify an existing device PM QoS request.
> + * @req : PM QoS request to modify.
> + * @new_value: New value to request.
> + */
> +int __dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value)
> +{
> + s32 curr_value;
> + int ret = 0;
> +
> + if (!req->dev->power.qos) {
> + ret = -ENODEV;
> + goto out;
> + }
> +
> + switch(req->type) {
> + case DEV_PM_QOS_LATENCY:
> + curr_value = req->data.pnode.prio;
> + break;
> + case DEV_PM_QOS_FLAGS:
> + curr_value = req->data.flr.flags;
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + if (curr_value != new_value)
> + ret = apply_constraint(req, PM_QOS_UPDATE_REQ, new_value);
> +
> + return ret;
> +}
> +
> +/**
> * dev_pm_qos_update_request - modifies an existing qos request
> * @req : handle to list element holding a dev_pm_qos request to use
> * @new_value: defines the qos request
> @@ -336,11 +369,9 @@ EXPORT_SYMBOL_GPL(dev_pm_qos_add_request
> * -EINVAL in case of wrong parameters, -ENODEV if the device has been
> * removed from the system
> */
> -int dev_pm_qos_update_request(struct dev_pm_qos_request *req,
> - s32 new_value)
> +int dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value)
> {
> - s32 curr_value;
> - int ret = 0;
> + int ret;
>
> if (!req) /*guard against callers passing in null */
> return -EINVAL;
> @@ -350,29 +381,9 @@ int dev_pm_qos_update_request(struct dev
> return -EINVAL;
>
> mutex_lock(&dev_pm_qos_mtx);
> -
> - if (!req->dev->power.qos) {
> - ret = -ENODEV;
> - goto out;
> - }
> -
> - switch(req->type) {
> - case DEV_PM_QOS_LATENCY:
> - curr_value = req->data.pnode.prio;
> - break;
> - case DEV_PM_QOS_FLAGS:
> - curr_value = req->data.flr.flags;
> - break;
> - default:
> - ret = -EINVAL;
> - goto out;
> - }
> -
> - if (curr_value != new_value)
> - ret = apply_constraint(req, PM_QOS_UPDATE_REQ, new_value);
> -
> - out:
> + __dev_pm_qos_update_request(req, new_value);
You forgot to assign the return value here.
Thanks,
Aaron
> mutex_unlock(&dev_pm_qos_mtx);
> +
> return ret;
> }
> EXPORT_SYMBOL_GPL(dev_pm_qos_update_request);
> @@ -533,10 +544,19 @@ int dev_pm_qos_add_ancestor_request(stru
> EXPORT_SYMBOL_GPL(dev_pm_qos_add_ancestor_request);
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