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 --- Documentation/power/runtime_pm.rst | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'Documentation/power') diff --git a/Documentation/power/runtime_pm.rst b/Documentation/power/runtime_pm.rst index 65b86e487afe..da99379071a4 100644 --- a/Documentation/power/runtime_pm.rst +++ b/Documentation/power/runtime_pm.rst @@ -396,10 +396,9 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h: nonzero, increment the counter and return 1; otherwise return 0 without changing the counter - `int pm_runtime_get_if_active(struct device *dev, bool ign_usage_count);` + `int pm_runtime_get_if_active(struct device *dev);` - return -EINVAL if 'power.disable_depth' is nonzero; otherwise, if the - runtime PM status is RPM_ACTIVE, and either ign_usage_count is true - or the device's usage_count is non-zero, increment the counter and + runtime PM status is RPM_ACTIVE, increment the counter and return 1; otherwise return 0 without changing the counter `void pm_runtime_put_noidle(struct device *dev);` -- 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 'Documentation/power') 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 e65095686441e724e5c64bf065d66e189048b4d5 Mon Sep 17 00:00:00 2001 From: Yiwei Lin Date: Sun, 25 Feb 2024 21:00:57 +0800 Subject: Documentation: PM: Fix runtime_pm.rst markdown syntax The '7. Generic subsystem callbacks' should be a section title, but the markdown syntax is not adequate now. Fix it so the chapter can be linked at docs.kernel.org correctly. Signed-off-by: Yiwei Lin [ rjw: Changelog edits ] Signed-off-by: Rafael J. Wysocki --- Documentation/power/runtime_pm.rst | 1 + 1 file changed, 1 insertion(+) (limited to 'Documentation/power') diff --git a/Documentation/power/runtime_pm.rst b/Documentation/power/runtime_pm.rst index 6fa50e4f87ce..5c4e730f38d0 100644 --- a/Documentation/power/runtime_pm.rst +++ b/Documentation/power/runtime_pm.rst @@ -734,6 +734,7 @@ out the following operations: for it, respectively. 7. Generic subsystem callbacks +============================== Subsystems may wish to conserve code space by using the set of generic power management callbacks provided by the PM core, defined in -- cgit v1.2.3