This is a note to let you know that I've just added the patch titled amba: Fix resource leak for drivers without .remove to the 5.4-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: amba-fix-resource-leak-for-drivers-without-.remove.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit e0a220bc8e9c01f0f125a197eb84e9c7608ce3c0 Author: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx> Date: Tue Jan 26 17:58:31 2021 +0100 amba: Fix resource leak for drivers without .remove [ Upstream commit de5d7adb89367bbc87b4e5ce7afe7ae9bd86dc12 ] Consider an amba driver with a .probe but without a .remove callback (e.g. pl061_gpio_driver). The function amba_probe() is called to bind a device and so dev_pm_domain_attach() and others are called. As there is no remove callback amba_remove() isn't called at unbind time however and so calling dev_pm_domain_detach() is missed and the pm domain keeps active. To fix this always use the core driver callbacks and handle missing amba callbacks there. For probe refuse registration as a driver without probe doesn't make sense. Fixes: 7cfe249475fd ("ARM: AMBA: Add pclk support to AMBA bus infrastructure") Reviewed-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx> Reviewed-by: Arnd Bergmann <arnd@xxxxxxxx> Link: https://lore.kernel.org/r/20210126165835.687514-2-u.kleine-koenig@xxxxxxxxxxxxxx Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c index fe1523664816a..af58768a03937 100644 --- a/drivers/amba/bus.c +++ b/drivers/amba/bus.c @@ -299,10 +299,11 @@ static int amba_remove(struct device *dev) { struct amba_device *pcdev = to_amba_device(dev); struct amba_driver *drv = to_amba_driver(dev->driver); - int ret; + int ret = 0; pm_runtime_get_sync(dev); - ret = drv->remove(pcdev); + if (drv->remove) + ret = drv->remove(pcdev); pm_runtime_put_noidle(dev); /* Undo the runtime PM settings in amba_probe() */ @@ -319,7 +320,9 @@ static int amba_remove(struct device *dev) static void amba_shutdown(struct device *dev) { struct amba_driver *drv = to_amba_driver(dev->driver); - drv->shutdown(to_amba_device(dev)); + + if (drv->shutdown) + drv->shutdown(to_amba_device(dev)); } /** @@ -332,12 +335,13 @@ static void amba_shutdown(struct device *dev) */ int amba_driver_register(struct amba_driver *drv) { - drv->drv.bus = &amba_bustype; + if (!drv->probe) + return -EINVAL; -#define SETFN(fn) if (drv->fn) drv->drv.fn = amba_##fn - SETFN(probe); - SETFN(remove); - SETFN(shutdown); + drv->drv.bus = &amba_bustype; + drv->drv.probe = amba_probe; + drv->drv.remove = amba_remove; + drv->drv.shutdown = amba_shutdown; return driver_register(&drv->drv); }