From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Linux PM <linux-pm@vger.kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Alan Stern <stern@rowland.harvard.edu>,
Ulf Hansson <ulf.hansson@linaro.org>,
Johan Hovold <johan@kernel.org>
Subject: [PATCH v1] PM: Rearrange documentation related to __pm_runtime_disable()
Date: Mon, 17 Feb 2025 21:03:01 +0100 [thread overview]
Message-ID: <12617588.O9o76ZdvQC@rjwysocki.net> (raw)
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There are only two callers of __pm_runtime_disable(), one of which is
device_suspend_late() and the other is pm_runtime_disable() that has
its own kerneldoc comment and there are no plans to add any more of
them. Since they use different values of the __pm_runtime_disable()
second parameter, the actual code behavior is different in each case,
but it is all documented in the __pm_runtime_disable() kerneldoc comment
which is not particularly straightforward.
For this reason, move the information from the __pm_runtime_disable()
kerneldoc comment to the pm_runtime_disable() one and into a separate
comment in device_suspend_late() and remove the __pm_runtime_disable()
kerneldoc comment altogether.
No functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
drivers/base/power/main.c | 4 ++++
drivers/base/power/runtime.c | 14 --------------
include/linux/pm_runtime.h | 15 +++++++++++----
3 files changed, 15 insertions(+), 18 deletions(-)
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -1404,6 +1404,10 @@
TRACE_DEVICE(dev);
TRACE_SUSPEND(0);
+ /*
+ * Disable runtime PM for the device without checking if there is a
+ * pending resume request for it.
+ */
__pm_runtime_disable(dev, false);
dpm_wait_for_subordinate(dev, async);
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -1460,20 +1460,6 @@
}
EXPORT_SYMBOL_GPL(pm_runtime_barrier);
-/**
- * __pm_runtime_disable - Disable runtime PM of a device.
- * @dev: Device to handle.
- * @check_resume: If set, check if there's a resume request for the device.
- *
- * Increment power.disable_depth for the device and if it was zero previously,
- * cancel all pending runtime PM requests for the device and wait for all
- * operations in progress to complete. The device can be either active or
- * suspended after its runtime PM has been disabled.
- *
- * If @check_resume is set and there's a resume request pending when
- * __pm_runtime_disable() is called and power.disable_depth is zero, the
- * function will wake up the device before disabling its runtime PM.
- */
void __pm_runtime_disable(struct device *dev, bool check_resume)
{
spin_lock_irq(&dev->power.lock);
--- a/include/linux/pm_runtime.h
+++ b/include/linux/pm_runtime.h
@@ -556,11 +556,18 @@
* pm_runtime_disable - Disable runtime PM for a device.
* @dev: Target device.
*
- * Prevent the runtime PM framework from working with @dev (by incrementing its
- * "blocking" counter).
+ * Prevent the runtime PM framework from working with @dev by incrementing its
+ * "disable" counter.
*
- * For each invocation of this function for @dev there must be a matching
- * pm_runtime_enable() call in order for runtime PM to be enabled for it.
+ * If the counter is zero when this function runs and there is a pending runtime
+ * resume request for @dev, it will be resumed. If the counter is still zero at
+ * that point, all of the pending runtime PM requests for @dev will be canceled
+ * and all runtime PM operations in progress involving it will be waited for to
+ * complete.
+ *
+ * For each invocation of this function for @dev, there must be a matching
+ * pm_runtime_enable() call, so that runtime PM is eventually enabled for it
+ * again.
*/
static inline void pm_runtime_disable(struct device *dev)
{
next reply other threads:[~2025-02-17 20:03 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-17 20:03 Rafael J. Wysocki [this message]
2025-02-18 11:09 ` Ulf Hansson
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