From mboxrd@z Thu Jan 1 00:00:00 1970 From: Krzysztof Kozlowski Subject: [PATCH v6 15/22] power_supply: Increment power supply use counter when obtaining references Date: Tue, 10 Mar 2015 09:27:19 +0100 Message-ID: <1425976046-20973-16-git-send-email-k.kozlowski@samsung.com> References: <1425976046-20973-1-git-send-email-k.kozlowski@samsung.com> Return-path: In-reply-to: <1425976046-20973-1-git-send-email-k.kozlowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Sebastian Reichel , Dmitry Eremin-Solenikov , David Woodhouse , "Rafael J. Wysocki" , Len Brown , Jiri Kosina , David Herrmann , Cezary Jackiewicz , Darren Hart , Support Opensource , Milo Kim , Linus Walleij , Samuel Ortiz , Lee Jones , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Ingo Molnar , "H. Peter Anvin" , x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, Daniel Mack , Haojian Zhuang , Robert Jarzmik , linux-pm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-acpi-u79uwXL29TY76Z2rM5mHXA@public.gmane.orglinux- Cc: Thomas Gleixner , Pavel Machek , Kyungmin Park , Marek Szyprowski , Krzysztof Kozlowski List-Id: linux-input@vger.kernel.org Increment the power_supply.use_cnt usage counter on: - power_supply_get_by_phandle() - power_supply_get_by_name() and decrement it on power_supply_put() call. This helps tracking of valid usage of power supply instance by consumers. The usage counter itself also allows safe calling of power_supply_get_property-like functions even when driver unregisters this power supply. Signed-off-by: Krzysztof Kozlowski Reviewed-by: Bartlomiej Zolnierkiewicz --- drivers/power/power_supply_core.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c index b4ec14683b7f..2ed4a4a6b3c5 100644 --- a/drivers/power/power_supply_core.c +++ b/drivers/power/power_supply_core.c @@ -349,10 +349,16 @@ static int power_supply_match_device_by_name(struct device *dev, const void *dat */ struct power_supply *power_supply_get_by_name(const char *name) { + struct power_supply *psy = NULL; struct device *dev = class_find_device(power_supply_class, NULL, name, power_supply_match_device_by_name); - return dev ? dev_get_drvdata(dev) : NULL; + if (dev) { + psy = dev_get_drvdata(dev); + atomic_inc(&psy->use_cnt); + } + + return psy; } EXPORT_SYMBOL_GPL(power_supply_get_by_name); @@ -367,6 +373,7 @@ void power_supply_put(struct power_supply *psy) { might_sleep(); + atomic_dec(&psy->use_cnt); put_device(&psy->dev); } EXPORT_SYMBOL_GPL(power_supply_put); @@ -393,6 +400,7 @@ struct power_supply *power_supply_get_by_phandle(struct device_node *np, const char *property) { struct device_node *power_supply_np; + struct power_supply *psy = NULL; struct device *dev; power_supply_np = of_parse_phandle(np, property, 0); @@ -404,7 +412,12 @@ struct power_supply *power_supply_get_by_phandle(struct device_node *np, of_node_put(power_supply_np); - return dev ? dev_get_drvdata(dev) : NULL; + if (dev) { + psy = dev_get_drvdata(dev); + atomic_inc(&psy->use_cnt); + } + + return psy; } EXPORT_SYMBOL_GPL(power_supply_get_by_phandle); #endif /* CONFIG_OF */ -- 1.9.1