Commit b4060db9 authored by Douglas Anderson's avatar Douglas Anderson Committed by Rafael J. Wysocki
Browse files

PM: runtime: Have devm_pm_runtime_enable() handle pm_runtime_dont_use_autosuspend() 



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: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: default avatarDouglas Anderson <dianders@chromium.org>
Reviewed-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 7e57714c

drivers/base/power/runtime.c

+5 −0
Original line number Diff line number Diff line
@@ -1476,11 +1476,16 @@ 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)

include/linux/pm_runtime.h

+4 −0
Original line number Diff line number Diff line
@@ -567,6 +567,10 @@ 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)

{