From c0ef3df8dbaef51ee4cfd58a471adf2eaee6f6b3 Mon Sep 17 00:00:00 2001 From: Sakari Ailus Date: Tue, 30 Jan 2024 13:28:05 +0200 Subject: PM: runtime: Simplify pm_runtime_get_if_active() usage There are two ways to opportunistically increment a device's runtime PM usage count, calling either pm_runtime_get_if_active() or pm_runtime_get_if_in_use(). The former has an argument to tell whether to ignore the usage count or not, and the latter simply calls the former with ign_usage_count set to false. The other users that want to ignore the usage_count will have to explicitly set that argument to true which is a bit cumbersome. To make this function more practical to use, remove the ign_usage_count argument from the function. The main implementation is in a static function called pm_runtime_get_conditional() and implementations of pm_runtime_get_if_active() and pm_runtime_get_if_in_use() are moved to runtime.c. Signed-off-by: Sakari Ailus Reviewed-by: Alex Elder Reviewed-by: Laurent Pinchart Acked-by: Takashi Iwai # sound/ Reviewed-by: Jacek Lawrynowicz # drivers/accel/ivpu/ Acked-by: Rodrigo Vivi # drivers/gpu/drm/i915/ Reviewed-by: Rodrigo Vivi Acked-by: Bjorn Helgaas # drivers/pci/ Signed-off-by: Rafael J. Wysocki --- include/linux/pm_runtime.h | 18 +++--------------- 1 file changed, 3 insertions(+), 15 deletions(-) (limited to 'include') diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h index 7c9b35448563..436baa167498 100644 --- a/include/linux/pm_runtime.h +++ b/include/linux/pm_runtime.h @@ -72,7 +72,8 @@ extern int pm_runtime_force_resume(struct device *dev); extern int __pm_runtime_idle(struct device *dev, int rpmflags); extern int __pm_runtime_suspend(struct device *dev, int rpmflags); extern int __pm_runtime_resume(struct device *dev, int rpmflags); -extern int pm_runtime_get_if_active(struct device *dev, bool ign_usage_count); +extern int pm_runtime_get_if_active(struct device *dev); +extern int pm_runtime_get_if_in_use(struct device *dev); extern int pm_schedule_suspend(struct device *dev, unsigned int delay); extern int __pm_runtime_set_status(struct device *dev, unsigned int status); extern int pm_runtime_barrier(struct device *dev); @@ -94,18 +95,6 @@ extern void pm_runtime_release_supplier(struct device_link *link); extern int devm_pm_runtime_enable(struct device *dev); -/** - * pm_runtime_get_if_in_use - Conditionally bump up runtime PM usage counter. - * @dev: Target device. - * - * Increment the runtime PM usage counter of @dev if its runtime PM status is - * %RPM_ACTIVE and its runtime PM usage counter is greater than 0. - */ -static inline int pm_runtime_get_if_in_use(struct device *dev) -{ - return pm_runtime_get_if_active(dev, false); -} - /** * pm_suspend_ignore_children - Set runtime PM behavior regarding children. * @dev: Target device. @@ -275,8 +264,7 @@ static inline int pm_runtime_get_if_in_use(struct device *dev) { return -EINVAL; } -static inline int pm_runtime_get_if_active(struct device *dev, - bool ign_usage_count) +static inline int pm_runtime_get_if_active(struct device *dev) { return -EINVAL; } -- cgit v1.2.3 From b7d46644e554ed017dfabc0841acf418d0584bc9 Mon Sep 17 00:00:00 2001 From: Sakari Ailus Date: Tue, 30 Jan 2024 13:28:32 +0200 Subject: PM: runtime: Add pm_runtime_put_autosuspend() replacement Add __pm_runtime_put_autosuspend() that replaces pm_runtime_put_autosuspend() for new users. The intent is to later re-purpose pm_runtime_put_autosuspend() to also mark the device's last busy stamp---which is what the vast majority of users actually need. This is also described in pm_runtime_put_autosuspend() documentation. Signed-off-by: Sakari Ailus Reviewed-by: Laurent Pinchart Signed-off-by: Rafael J. Wysocki --- Documentation/power/runtime_pm.rst | 17 +++++++++++------ include/linux/pm_runtime.h | 12 ++++++++++++ 2 files changed, 23 insertions(+), 6 deletions(-) (limited to 'include') diff --git a/Documentation/power/runtime_pm.rst b/Documentation/power/runtime_pm.rst index da99379071a4..6fa50e4f87ce 100644 --- a/Documentation/power/runtime_pm.rst +++ b/Documentation/power/runtime_pm.rst @@ -154,7 +154,7 @@ 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 +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 @@ -409,6 +409,10 @@ 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! + + `int __pm_runtime_put_autosuspend(struct device *dev);` - decrement the device's usage counter; if the result is 0 then run pm_request_autosuspend(dev) and return its result @@ -539,6 +543,7 @@ It is safe to execute the following helper functions from interrupt context: - pm_runtime_put_noidle() - pm_runtime_put() - pm_runtime_put_autosuspend() +- __pm_runtime_put_autosuspend() - pm_runtime_enable() - pm_suspend_ignore_children() - pm_runtime_set_active() @@ -864,9 +869,9 @@ 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 +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 registration the length should be controlled by user space, using the /sys/devices/.../power/autosuspend_delay_ms attribute. @@ -877,7 +882,7 @@ 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 @@ -916,7 +921,7 @@ Here is a schematic pseudo-code example:: lock(&foo->private_lock); if (--foo->num_pending_requests == 0) { pm_runtime_mark_last_busy(&foo->dev); - pm_runtime_put_autosuspend(&foo->dev); + __pm_runtime_put_autosuspend(&foo->dev); } else { foo_process_next_request(foo); } diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h index 436baa167498..d39dc863f612 100644 --- a/include/linux/pm_runtime.h +++ b/include/linux/pm_runtime.h @@ -448,6 +448,18 @@ static inline int pm_runtime_put(struct device *dev) return __pm_runtime_idle(dev, RPM_GET_PUT | RPM_ASYNC); } +/** + * __pm_runtime_put_autosuspend - Drop device usage counter and queue autosuspend if 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(). + */ +static inline int __pm_runtime_put_autosuspend(struct device *dev) +{ + return __pm_runtime_suspend(dev, RPM_GET_PUT | RPM_ASYNC | RPM_AUTO); +} + /** * pm_runtime_put_autosuspend - Drop device usage counter and queue autosuspend if 0. * @dev: Target device. -- cgit v1.2.3 From 015abee404760249a5c968b9ce29216b94b8ced1 Mon Sep 17 00:00:00 2001 From: Vilas Bhat Date: Wed, 21 Feb 2024 19:47:53 +0000 Subject: PM: runtime: add tracepoint for runtime_status changes Existing runtime PM ftrace events (`rpm_suspend`, `rpm_resume`, `rpm_return_int`) offer limited visibility into the exact timing of device runtime power state transitions, particularly when asynchronous operations are involved. When the `rpm_suspend` or `rpm_resume` functions are invoked with the `RPM_ASYNC` flag, a return value of 0 i.e., success merely indicates that the device power state request has been queued, not that the device has yet transitioned. A new ftrace event, `rpm_status`, is introduced. This event directly logs the `power.runtime_status` value of a device whenever it changes providing granular tracking of runtime power state transitions regardless of synchronous or asynchronous `rpm_suspend` / `rpm_resume` usage. Signed-off-by: Vilas Bhat Signed-off-by: Rafael J. Wysocki --- drivers/base/power/runtime.c | 1 + include/trace/events/rpm.h | 42 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 43 insertions(+) (limited to 'include') diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 5275a6b2e980..2ee45841486b 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -94,6 +94,7 @@ static void update_pm_runtime_accounting(struct device *dev) static void __update_runtime_status(struct device *dev, enum rpm_status status) { update_pm_runtime_accounting(dev); + trace_rpm_status(dev, status); dev->power.runtime_status = status; } diff --git a/include/trace/events/rpm.h b/include/trace/events/rpm.h index 3c716214dab1..bd120e23ce12 100644 --- a/include/trace/events/rpm.h +++ b/include/trace/events/rpm.h @@ -101,6 +101,48 @@ TRACE_EVENT(rpm_return_int, __entry->ret) ); +#define RPM_STATUS_STRINGS \ + EM(RPM_INVALID, "RPM_INVALID") \ + EM(RPM_ACTIVE, "RPM_ACTIVE") \ + EM(RPM_RESUMING, "RPM_RESUMING") \ + EM(RPM_SUSPENDED, "RPM_SUSPENDED") \ + EMe(RPM_SUSPENDING, "RPM_SUSPENDING") + +/* Enums require being exported to userspace, for user tool parsing. */ +#undef EM +#undef EMe +#define EM(a, b) TRACE_DEFINE_ENUM(a); +#define EMe(a, b) TRACE_DEFINE_ENUM(a); + +RPM_STATUS_STRINGS + +/* + * Now redefine the EM() and EMe() macros to map the enums to the strings that + * will be printed in the output. + */ +#undef EM +#undef EMe +#define EM(a, b) { a, b }, +#define EMe(a, b) { a, b } + +TRACE_EVENT(rpm_status, + TP_PROTO(struct device *dev, enum rpm_status status), + TP_ARGS(dev, status), + + TP_STRUCT__entry( + __string(name, dev_name(dev)) + __field(int, status) + ), + + TP_fast_assign( + __assign_str(name, dev_name(dev)); + __entry->status = status; + ), + + TP_printk("%s status=%s", __get_str(name), + __print_symbolic(__entry->status, RPM_STATUS_STRINGS)) +); + #endif /* _TRACE_RUNTIME_POWER_H */ /* This part must be outside protection */ -- cgit v1.2.3