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Message-Id: <20220223083441.1.I925ce9fa12992a58caed6b297e0171d214866fe7@changeid> Date: Wed, 23 Feb 2022 08:34:48 -0800 From: Douglas Anderson <dianders@...omium.org> To: "Rafael J . Wysocki" <rafael@...nel.org> Cc: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>, Linus Walleij <linus.walleij@...aro.org>, Stephen Boyd <sboyd@...nel.org>, Laurent Pinchart <laurent.pinchart@...asonboard.com>, Douglas Anderson <dianders@...omium.org>, Greg Kroah-Hartman <gregkh@...uxfoundation.org>, Len Brown <len.brown@...el.com>, Pavel Machek <pavel@....cz>, linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org Subject: [PATCH] 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: Laurent Pinchart <laurent.pinchart@...asonboard.com> Signed-off-by: Douglas Anderson <dianders@...omium.org> --- 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 2f3cce17219b..d4059e6ffeae 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -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) diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h index 9f09601c465a..2bff6a10095d 100644 --- a/include/linux/pm_runtime.h +++ b/include/linux/pm_runtime.h @@ -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) { -- 2.35.1.473.g83b2b277ed-goog
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