This is a note to let you know that I've just added the patch titled
PM: runtime: Have devm_pm_runtime_enable() handle pm_runtime_dont_use_autosuspend()
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pm-runtime-have-devm_pm_runtime_enable-handle-pm_runtime_dont_use_autosuspend.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From stable+bounces-17402-greg=kroah.com@xxxxxxxxxxxxxxx Tue Jan 30 13:46:51 2024
From: Amit Pundir <amit.pundir@xxxxxxxxxx>
Date: Tue, 30 Jan 2024 18:16:29 +0530
Subject: PM: runtime: Have devm_pm_runtime_enable() handle pm_runtime_dont_use_autosuspend()
To: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>, Sasha Levin <sashal@xxxxxxxxxx>, Konrad Dybcio <konrad.dybcio@xxxxxxxxxx>, Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>, Douglas Anderson <dianders@xxxxxxxxxxxx>
Cc: Stable <stable@xxxxxxxxxxxxxxx>, Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>, Ulf Hansson <ulf.hansson@xxxxxxxxxx>, "Rafael J . Wysocki" <rafael.j.wysocki@xxxxxxxxx>
Message-ID: <20240130124630.3867218-3-amit.pundir@xxxxxxxxxx>
From: Douglas Anderson <dianders@xxxxxxxxxxxx>
[ Upstream commit b4060db9251f919506e4d672737c6b8ab9a84701 ]
The PM Runtime docs say:
Drivers in ->remove() callback should undo the runtime PM changes done
in ->probe(). Usually this means calling pm_runtime_disable(),
pm_runtime_dont_use_autosuspend() etc.
>From grepping code, it's clear that many people aren't aware of the
need to call pm_runtime_dont_use_autosuspend().
When brainstorming solutions, one idea that came up was to leverage
the new-ish devm_pm_runtime_enable() function. The idea here is that:
* When the devm action is called we know that the driver is being
removed. It's the perfect time to undo the use_autosuspend.
* The code of pm_runtime_dont_use_autosuspend() already handles the
case of being called when autosuspend wasn't enabled.
Suggested-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Reviewed-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Stable-dep-of: 3d07a411b4fa ("drm/msm/dsi: Use pm_runtime_resume_and_get to prevent refcnt leaks")
Signed-off-by: Amit Pundir <amit.pundir@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/base/power/runtime.c | 5 +++++
include/linux/pm_runtime.h | 4 ++++
2 files changed, 9 insertions(+)
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -1481,11 +1481,16 @@ EXPORT_SYMBOL_GPL(pm_runtime_enable);
static void pm_runtime_disable_action(void *data)
{
+ pm_runtime_dont_use_autosuspend(data);
pm_runtime_disable(data);
}
/**
* devm_pm_runtime_enable - devres-enabled version of pm_runtime_enable.
+ *
+ * NOTE: this will also handle calling pm_runtime_dont_use_autosuspend() for
+ * you at driver exit time if needed.
+ *
* @dev: Device to handle.
*/
int devm_pm_runtime_enable(struct device *dev)
--- a/include/linux/pm_runtime.h
+++ b/include/linux/pm_runtime.h
@@ -539,6 +539,10 @@ static inline void pm_runtime_disable(st
* Allow the runtime PM autosuspend mechanism to be used for @dev whenever
* requested (or "autosuspend" will be handled as direct runtime-suspend for
* it).
+ *
+ * NOTE: It's important to undo this with pm_runtime_dont_use_autosuspend()
+ * at driver exit time unless your driver initially enabled pm_runtime
+ * with devm_pm_runtime_enable() (which handles it for you).
*/
static inline void pm_runtime_use_autosuspend(struct device *dev)
{
Patches currently in stable-queue which might be from kroah.com@xxxxxxxxxxxxxxx are
queue-5.10/smb3-replace-smb2pdu-1-element-arrays-with-flex-arrays.patch
queue-5.10/drm-msm-dsi-enable-runtime-pm.patch
queue-5.10/pm-runtime-have-devm_pm_runtime_enable-handle-pm_runtime_dont_use_autosuspend.patch
queue-5.10/stddef-introduce-declare_flex_array-helper.patch
queue-5.10/pm-runtime-add-devm_pm_runtime_enable-helper.patch
