From 14b6257a5f3dca3817b0826cb32967e3c2b935c8 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Fri, 4 Dec 2015 23:49:17 +0200 Subject: device core: add BUS_NOTIFY_DRIVER_NOT_BOUND notification The users of BUS_NOTIFY_BIND_DRIVER have no chance to do any cleanup in case of a probe failure. In the result there might be problems, such as some resources that had been allocated will continue to be allocated and therefore lead to a resource leak. Introduce a new notification to inform the subscriber that ->probe() failed. Do the same in case of failed device_bind_driver() call. Signed-off-by: Andy Shevchenko Acked-by: Greg Kroah-Hartman Signed-off-by: Rafael J. Wysocki --- include/linux/device.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/device.h') diff --git a/include/linux/device.h b/include/linux/device.h index b8f411b57dcb..f627ba20a46c 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -191,6 +191,7 @@ extern int bus_unregister_notifier(struct bus_type *bus, unbound */ #define BUS_NOTIFY_UNBOUND_DRIVER 0x00000007 /* driver is unbound from the device */ +#define BUS_NOTIFY_DRIVER_NOT_BOUND 0x00000008 /* driver fails to be bound */ extern struct kset *bus_get_kset(struct bus_type *bus); extern struct klist *bus_get_device_klist(struct bus_type *bus); -- cgit v1.2.3 From 6b9cb42752dafba3761dde0002ca58ca518b6311 Mon Sep 17 00:00:00 2001 From: Tomeu Vizoso Date: Thu, 7 Jan 2016 16:46:12 +0100 Subject: device core: add device_is_bound() Adds a function that tells whether a device is already bound to a driver. This is needed to warn when there is an attempt to change the PM domain of a device that has finished probing already. The reason why we want to enforce that is because in the general case that can cause problems and also that we can simplify code quite a bit if we can always assume that. Signed-off-by: Tomeu Vizoso Reviewed-by: Ulf Hansson Acked-by: Greg Kroah-Hartman Signed-off-by: Rafael J. Wysocki --- drivers/base/dd.c | 18 ++++++++++++++++-- include/linux/device.h | 2 ++ 2 files changed, 18 insertions(+), 2 deletions(-) (limited to 'include/linux/device.h') diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 7399be790b5d..13a0d66e5782 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -223,9 +223,23 @@ static int deferred_probe_initcall(void) } late_initcall(deferred_probe_initcall); +/** + * device_is_bound() - Check if device is bound to a driver + * @dev: device to check + * + * Returns true if passed device has already finished probing successfully + * against a driver. + * + * This function must be called with the device lock held. + */ +bool device_is_bound(struct device *dev) +{ + return klist_node_attached(&dev->p->knode_driver); +} + static void driver_bound(struct device *dev) { - if (klist_node_attached(&dev->p->knode_driver)) { + if (device_is_bound(dev)) { printk(KERN_WARNING "%s: device %s already bound\n", __func__, kobject_name(&dev->kobj)); return; @@ -601,7 +615,7 @@ static int __device_attach(struct device *dev, bool allow_async) device_lock(dev); if (dev->driver) { - if (klist_node_attached(&dev->p->knode_driver)) { + if (device_is_bound(dev)) { ret = 1; goto out_unlock; } diff --git a/include/linux/device.h b/include/linux/device.h index f627ba20a46c..6d6f1fec092f 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -1044,6 +1044,8 @@ extern int __must_check driver_attach(struct device_driver *drv); extern void device_initial_probe(struct device *dev); extern int __must_check device_reprobe(struct device *dev); +extern bool device_is_bound(struct device *dev); + /* * Easy functions for dynamically creating devices on the fly */ -- cgit v1.2.3