diff options
| -rw-r--r-- | Documentation/power/runtime_pm.rst | 50 | ||||
| -rw-r--r-- | drivers/regulator/stm32-vrefbuf.c | 6 | ||||
| -rw-r--r-- | include/linux/pm_runtime.h | 187 |
3 files changed, 186 insertions, 57 deletions
diff --git a/Documentation/power/runtime_pm.rst b/Documentation/power/runtime_pm.rst index 63344bea8393..c8dbdb8595e5 100644 --- a/Documentation/power/runtime_pm.rst +++ b/Documentation/power/runtime_pm.rst @@ -154,11 +154,9 @@ suspending the device are satisfied) and to queue up a suspend request for the device in that case. If there is no idle callback, or if the callback returns 0, then the PM core will attempt to carry out a runtime suspend of the device, also respecting devices configured for autosuspend. In essence this means a -call to pm_runtime_autosuspend() (do note that drivers needs to update the -device last busy mark, pm_runtime_mark_last_busy(), to control the delay under -this circumstance). To prevent this (for example, if the callback routine has -started a delayed suspend), the routine must return a non-zero value. Negative -error return codes are ignored by the PM core. +call to pm_runtime_autosuspend(). To prevent this (for example, if the callback +routine has started a delayed suspend), the routine must return a non-zero +value. Negative error return codes are ignored by the PM core. The helper functions provided by the PM core, described in Section 4, guarantee that the following constraints are met with respect to runtime PM callbacks for @@ -330,10 +328,9 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h: 'power.disable_depth' is different from 0 `int pm_runtime_autosuspend(struct device *dev);` - - same as pm_runtime_suspend() except that the autosuspend delay is taken - `into account;` if pm_runtime_autosuspend_expiration() says the delay has - not yet expired then an autosuspend is scheduled for the appropriate time - and 0 is returned + - same as pm_runtime_suspend() except that a call to + pm_runtime_mark_last_busy() is made and an autosuspend is scheduled for + the appropriate time and 0 is returned `int pm_runtime_resume(struct device *dev);` - execute the subsystem-level resume callback for the device; returns 0 on @@ -357,9 +354,9 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h: success or error code if the request has not been queued up `int pm_request_autosuspend(struct device *dev);` - - schedule the execution of the subsystem-level suspend callback for the - device when the autosuspend delay has expired; if the delay has already - expired then the work item is queued up immediately + - Call pm_runtime_mark_last_busy() and schedule the execution of the + subsystem-level suspend callback for the device when the autosuspend delay + expires `int pm_schedule_suspend(struct device *dev, unsigned int delay);` - schedule the execution of the subsystem-level suspend callback for the @@ -411,8 +408,9 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h: pm_request_idle(dev) and return its result `int pm_runtime_put_autosuspend(struct device *dev);` - - does the same as __pm_runtime_put_autosuspend() for now, but in the - future, will also call pm_runtime_mark_last_busy() as well, DO NOT USE! + - set the power.last_busy field to the current time and decrement the + device's usage counter; if the result is 0 then run + pm_request_autosuspend(dev) and return its result `int __pm_runtime_put_autosuspend(struct device *dev);` - decrement the device's usage counter; if the result is 0 then run @@ -427,7 +425,8 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h: pm_runtime_suspend(dev) and return its result `int pm_runtime_put_sync_autosuspend(struct device *dev);` - - decrement the device's usage counter; if the result is 0 then run + - set the power.last_busy field to the current time and decrement the + device's usage counter; if the result is 0 then run pm_runtime_autosuspend(dev) and return its result `void pm_runtime_enable(struct device *dev);` @@ -870,11 +869,9 @@ device is automatically suspended (the subsystem or driver still has to call the appropriate PM routines); rather it means that runtime suspends will automatically be delayed until the desired period of inactivity has elapsed. -Inactivity is determined based on the power.last_busy field. Drivers should -call pm_runtime_mark_last_busy() to update this field after carrying out I/O, -typically just before calling __pm_runtime_put_autosuspend(). The desired -length of the inactivity period is a matter of policy. Subsystems can set this -length initially by calling pm_runtime_set_autosuspend_delay(), but after device +Inactivity is determined based on the power.last_busy field. The desired length +of the inactivity period is a matter of policy. Subsystems can set this length +initially by calling pm_runtime_set_autosuspend_delay(), but after device registration the length should be controlled by user space, using the /sys/devices/.../power/autosuspend_delay_ms attribute. @@ -885,12 +882,13 @@ instead of the non-autosuspend counterparts:: Instead of: pm_runtime_suspend use: pm_runtime_autosuspend; Instead of: pm_schedule_suspend use: pm_request_autosuspend; - Instead of: pm_runtime_put use: __pm_runtime_put_autosuspend; + Instead of: pm_runtime_put use: pm_runtime_put_autosuspend; Instead of: pm_runtime_put_sync use: pm_runtime_put_sync_autosuspend. Drivers may also continue to use the non-autosuspend helper functions; they will behave normally, which means sometimes taking the autosuspend delay into -account (see pm_runtime_idle). +account (see pm_runtime_idle). The autosuspend variants of the functions also +call pm_runtime_mark_last_busy(). Under some circumstances a driver or subsystem may want to prevent a device from autosuspending immediately, even though the usage counter is zero and the @@ -922,12 +920,10 @@ Here is a schematic pseudo-code example:: foo_io_completion(struct foo_priv *foo, void *req) { lock(&foo->private_lock); - if (--foo->num_pending_requests == 0) { - pm_runtime_mark_last_busy(&foo->dev); - __pm_runtime_put_autosuspend(&foo->dev); - } else { + if (--foo->num_pending_requests == 0) + pm_runtime_put_autosuspend(&foo->dev); + else foo_process_next_request(foo); - } unlock(&foo->private_lock); /* Send req result back to the user ... */ } diff --git a/drivers/regulator/stm32-vrefbuf.c b/drivers/regulator/stm32-vrefbuf.c index a85ea94f0673..9e391206f09d 100644 --- a/drivers/regulator/stm32-vrefbuf.c +++ b/drivers/regulator/stm32-vrefbuf.c @@ -67,7 +67,6 @@ static int stm32_vrefbuf_enable(struct regulator_dev *rdev) writel_relaxed(val, priv->base + STM32_VREFBUF_CSR); } - pm_runtime_mark_last_busy(priv->dev); pm_runtime_put_autosuspend(priv->dev); return ret; @@ -87,7 +86,6 @@ static int stm32_vrefbuf_disable(struct regulator_dev *rdev) val &= ~STM32_ENVR; writel_relaxed(val, priv->base + STM32_VREFBUF_CSR); - pm_runtime_mark_last_busy(priv->dev); pm_runtime_put_autosuspend(priv->dev); return 0; @@ -104,7 +102,6 @@ static int stm32_vrefbuf_is_enabled(struct regulator_dev *rdev) ret = readl_relaxed(priv->base + STM32_VREFBUF_CSR) & STM32_ENVR; - pm_runtime_mark_last_busy(priv->dev); pm_runtime_put_autosuspend(priv->dev); return ret; @@ -125,7 +122,6 @@ static int stm32_vrefbuf_set_voltage_sel(struct regulator_dev *rdev, val = (val & ~STM32_VRS) | FIELD_PREP(STM32_VRS, sel); writel_relaxed(val, priv->base + STM32_VREFBUF_CSR); - pm_runtime_mark_last_busy(priv->dev); pm_runtime_put_autosuspend(priv->dev); return 0; @@ -144,7 +140,6 @@ static int stm32_vrefbuf_get_voltage_sel(struct regulator_dev *rdev) val = readl_relaxed(priv->base + STM32_VREFBUF_CSR); ret = FIELD_GET(STM32_VRS, val); - pm_runtime_mark_last_busy(priv->dev); pm_runtime_put_autosuspend(priv->dev); return ret; @@ -218,7 +213,6 @@ static int stm32_vrefbuf_probe(struct platform_device *pdev) } platform_set_drvdata(pdev, rdev); - pm_runtime_mark_last_busy(&pdev->dev); pm_runtime_put_autosuspend(&pdev->dev); return 0; diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h index e7cb70fcc0af..778d5988f35e 100644 --- a/include/linux/pm_runtime.h +++ b/include/linux/pm_runtime.h @@ -337,6 +337,20 @@ static inline void pm_runtime_release_supplier(struct device_link *link) {} * Invoke the "idle check" callback of @dev and, depending on its return value, * set up autosuspend of @dev or suspend it (depending on whether or not * autosuspend has been enabled for it). + * + * Return: + * * 0: Success. + * * -EINVAL: Runtime PM error. + * * -EACCES: Runtime PM disabled. + * * -EAGAIN: Runtime PM usage_count non-zero, Runtime PM status change ongoing + * or device not in %RPM_ACTIVE state. + * * -EBUSY: Runtime PM child_count non-zero. + * * -EPERM: Device PM QoS resume latency 0. + * * -EINPROGRESS: Suspend already in progress. + * * -ENOSYS: CONFIG_PM not enabled. + * * 1: Device already suspended. + * Other values and conditions for the above values are possible as returned by + * Runtime PM idle and suspend callbacks. */ static inline int pm_runtime_idle(struct device *dev) { @@ -346,6 +360,18 @@ static inline int pm_runtime_idle(struct device *dev) /** * pm_runtime_suspend - Suspend a device synchronously. * @dev: Target device. + * + * Return: + * * 0: Success. + * * -EINVAL: Runtime PM error. + * * -EACCES: Runtime PM disabled. + * * -EAGAIN: Runtime PM usage_count non-zero or Runtime PM status change ongoing. + * * -EBUSY: Runtime PM child_count non-zero. + * * -EPERM: Device PM QoS resume latency 0. + * * -ENOSYS: CONFIG_PM not enabled. + * * 1: Device already suspended. + * Other values and conditions for the above values are possible as returned by + * Runtime PM suspend callbacks. */ static inline int pm_runtime_suspend(struct device *dev) { @@ -353,14 +379,29 @@ static inline int pm_runtime_suspend(struct device *dev) } /** - * pm_runtime_autosuspend - Set up autosuspend of a device or suspend it. + * pm_runtime_autosuspend - Update the last access time and set up autosuspend + * of a device. * @dev: Target device. * - * Set up autosuspend of @dev or suspend it (depending on whether or not - * autosuspend is enabled for it) without engaging its "idle check" callback. + * First update the last access time, then set up autosuspend of @dev or suspend + * it (depending on whether or not autosuspend is enabled for it) without + * engaging its "idle check" callback. + * + * Return: + * * 0: Success. + * * -EINVAL: Runtime PM error. + * * -EACCES: Runtime PM disabled. + * * -EAGAIN: Runtime PM usage_count non-zero or Runtime PM status change ongoing. + * * -EBUSY: Runtime PM child_count non-zero. + * * -EPERM: Device PM QoS resume latency 0. + * * -ENOSYS: CONFIG_PM not enabled. + * * 1: Device already suspended. + * Other values and conditions for the above values are possible as returned by + * Runtime PM suspend callbacks. */ static inline int pm_runtime_autosuspend(struct device *dev) { + pm_runtime_mark_last_busy(dev); return __pm_runtime_suspend(dev, RPM_AUTO); } @@ -379,6 +420,18 @@ static inline int pm_runtime_resume(struct device *dev) * * Queue up a work item to run an equivalent of pm_runtime_idle() for @dev * asynchronously. + * + * Return: + * * 0: Success. + * * -EINVAL: Runtime PM error. + * * -EACCES: Runtime PM disabled. + * * -EAGAIN: Runtime PM usage_count non-zero, Runtime PM status change ongoing + * or device not in %RPM_ACTIVE state. + * * -EBUSY: Runtime PM child_count non-zero. + * * -EPERM: Device PM QoS resume latency 0. + * * -EINPROGRESS: Suspend already in progress. + * * -ENOSYS: CONFIG_PM not enabled. + * * 1: Device already suspended. */ static inline int pm_request_idle(struct device *dev) { @@ -395,14 +448,27 @@ static inline int pm_request_resume(struct device *dev) } /** - * pm_request_autosuspend - Queue up autosuspend of a device. + * pm_request_autosuspend - Update the last access time and queue up autosuspend + * of a device. * @dev: Target device. * - * Queue up a work item to run an equivalent pm_runtime_autosuspend() for @dev - * asynchronously. + * Update the last access time of a device and queue up a work item to run an + * equivalent pm_runtime_autosuspend() for @dev asynchronously. + * + * Return: + * * 0: Success. + * * -EINVAL: Runtime PM error. + * * -EACCES: Runtime PM disabled. + * * -EAGAIN: Runtime PM usage_count non-zero or Runtime PM status change ongoing. + * * -EBUSY: Runtime PM child_count non-zero. + * * -EPERM: Device PM QoS resume latency 0. + * * -EINPROGRESS: Suspend already in progress. + * * -ENOSYS: CONFIG_PM not enabled. + * * 1: Device already suspended. */ static inline int pm_request_autosuspend(struct device *dev) { + pm_runtime_mark_last_busy(dev); return __pm_runtime_suspend(dev, RPM_ASYNC | RPM_AUTO); } @@ -464,6 +530,17 @@ static inline int pm_runtime_resume_and_get(struct device *dev) * * Decrement the runtime PM usage counter of @dev and if it turns out to be * equal to 0, queue up a work item for @dev like in pm_request_idle(). + * + * Return: + * * 0: Success. + * * -EINVAL: Runtime PM error. + * * -EACCES: Runtime PM disabled. + * * -EAGAIN: Runtime PM usage_count non-zero or Runtime PM status change ongoing. + * * -EBUSY: Runtime PM child_count non-zero. + * * -EPERM: Device PM QoS resume latency 0. + * * -EINPROGRESS: Suspend already in progress. + * * -ENOSYS: CONFIG_PM not enabled. + * * 1: Device already suspended. */ static inline int pm_runtime_put(struct device *dev) { @@ -478,6 +555,17 @@ DEFINE_FREE(pm_runtime_put, struct device *, if (_T) pm_runtime_put(_T)) * * Decrement the runtime PM usage counter of @dev and if it turns out to be * equal to 0, queue up a work item for @dev like in pm_request_autosuspend(). + * + * Return: + * * 0: Success. + * * -EINVAL: Runtime PM error. + * * -EACCES: Runtime PM disabled. + * * -EAGAIN: Runtime PM usage_count non-zero or Runtime PM status change ongoing. + * * -EBUSY: Runtime PM child_count non-zero. + * * -EPERM: Device PM QoS resume latency 0. + * * -EINPROGRESS: Suspend already in progress. + * * -ENOSYS: CONFIG_PM not enabled. + * * 1: Device already suspended. */ static inline int __pm_runtime_put_autosuspend(struct device *dev) { @@ -485,16 +573,29 @@ static inline int __pm_runtime_put_autosuspend(struct device *dev) } /** - * pm_runtime_put_autosuspend - Drop device usage counter and queue autosuspend if 0. + * pm_runtime_put_autosuspend - Update the last access time of a device, drop + * its usage counter and queue autosuspend if the usage counter becomes 0. * @dev: Target device. * - * Decrement the runtime PM usage counter of @dev and if it turns out to be - * equal to 0, queue up a work item for @dev like in pm_request_autosuspend(). + * Update the last access time of @dev, decrement runtime PM usage counter of + * @dev and if it turns out to be equal to 0, queue up a work item for @dev like + * in pm_request_autosuspend(). + * + * Return: + * * 0: Success. + * * -EINVAL: Runtime PM error. + * * -EACCES: Runtime PM disabled. + * * -EAGAIN: Runtime PM usage_count non-zero or Runtime PM status change ongoing. + * * -EBUSY: Runtime PM child_count non-zero. + * * -EPERM: Device PM QoS resume latency 0. + * * -EINPROGRESS: Suspend already in progress. + * * -ENOSYS: CONFIG_PM not enabled. + * * 1: Device already suspended. */ static inline int pm_runtime_put_autosuspend(struct device *dev) { - return __pm_runtime_suspend(dev, - RPM_GET_PUT | RPM_ASYNC | RPM_AUTO); + pm_runtime_mark_last_busy(dev); + return __pm_runtime_put_autosuspend(dev); } /** @@ -506,9 +607,20 @@ static inline int pm_runtime_put_autosuspend(struct device *dev) * return value, set up autosuspend of @dev or suspend it (depending on whether * or not autosuspend has been enabled for it). * - * The possible return values of this function are the same as for - * pm_runtime_idle() and the runtime PM usage counter of @dev remains - * decremented in all cases, even if it returns an error code. + * The runtime PM usage counter of @dev remains decremented in all cases, even + * if it returns an error code. + * + * Return: + * * 0: Success. + * * -EINVAL: Runtime PM error. + * * -EACCES: Runtime PM disabled. + * * -EAGAIN: Runtime PM usage_count non-zero or Runtime PM status change ongoing. + * * -EBUSY: Runtime PM child_count non-zero. + * * -EPERM: Device PM QoS resume latency 0. + * * -ENOSYS: CONFIG_PM not enabled. + * * 1: Device already suspended. + * Other values and conditions for the above values are possible as returned by + * Runtime PM suspend callbacks. */ static inline int pm_runtime_put_sync(struct device *dev) { @@ -522,9 +634,21 @@ static inline int pm_runtime_put_sync(struct device *dev) * Decrement the runtime PM usage counter of @dev and if it turns out to be * equal to 0, carry out runtime-suspend of @dev synchronously. * - * The possible return values of this function are the same as for - * pm_runtime_suspend() and the runtime PM usage counter of @dev remains - * decremented in all cases, even if it returns an error code. + * The runtime PM usage counter of @dev remains decremented in all cases, even + * if it returns an error code. + * + * Return: + * * 0: Success. + * * -EINVAL: Runtime PM error. + * * -EACCES: Runtime PM disabled. + * * -EAGAIN: Runtime PM usage_count non-zero or Runtime PM status change ongoing. + * * -EAGAIN: usage_count non-zero or Runtime PM status change ongoing. + * * -EBUSY: Runtime PM child_count non-zero. + * * -EPERM: Device PM QoS resume latency 0. + * * -ENOSYS: CONFIG_PM not enabled. + * * 1: Device already suspended. + * Other values and conditions for the above values are possible as returned by + * Runtime PM suspend callbacks. */ static inline int pm_runtime_put_sync_suspend(struct device *dev) { @@ -532,19 +656,34 @@ static inline int pm_runtime_put_sync_suspend(struct device *dev) } /** - * pm_runtime_put_sync_autosuspend - Drop device usage counter and autosuspend if 0. + * pm_runtime_put_sync_autosuspend - Update the last access time of a device, + * drop device usage counter and autosuspend if 0. * @dev: Target device. * - * Decrement the runtime PM usage counter of @dev and if it turns out to be - * equal to 0, set up autosuspend of @dev or suspend it synchronously (depending - * on whether or not autosuspend has been enabled for it). + * Update the last access time of @dev, decrement the runtime PM usage counter + * of @dev and if it turns out to be equal to 0, set up autosuspend of @dev or + * suspend it synchronously (depending on whether or not autosuspend has been + * enabled for it). * - * The possible return values of this function are the same as for - * pm_runtime_autosuspend() and the runtime PM usage counter of @dev remains - * decremented in all cases, even if it returns an error code. + * The runtime PM usage counter of @dev remains decremented in all cases, even + * if it returns an error code. + * + * Return: + * * 0: Success. + * * -EINVAL: Runtime PM error. + * * -EACCES: Runtime PM disabled. + * * -EAGAIN: Runtime PM usage_count non-zero or Runtime PM status change ongoing. + * * -EBUSY: Runtime PM child_count non-zero. + * * -EPERM: Device PM QoS resume latency 0. + * * -EINPROGRESS: Suspend already in progress. + * * -ENOSYS: CONFIG_PM not enabled. + * * 1: Device already suspended. + * Other values and conditions for the above values are possible as returned by + * Runtime PM suspend callbacks. */ static inline int pm_runtime_put_sync_autosuspend(struct device *dev) { + pm_runtime_mark_last_busy(dev); return __pm_runtime_suspend(dev, RPM_GET_PUT | RPM_AUTO); } |