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>
---
drivers/base/power/runtime.c | 5 +++++
include/linux/pm_runtime.h | 4 ++++
2 files changed, 9 insertions(+)
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index 5824d41a0b74..6699096ff2fa 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -1479,11 +1479,16 @@ 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)
diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h
index 90eaff8b78fc..7efb10518313 100644
--- a/include/linux/pm_runtime.h
+++ b/include/linux/pm_runtime.h
@@ -542,6 +542,10 @@ static inline void pm_runtime_disable(struct device *dev)
* 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)
{
--
2.25.1
