diff --git a/drivers/base/bus.c b/drivers/base/bus.c index ef6183306b40..8bfd27ec73d6 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -184,10 +184,10 @@ static ssize_t unbind_store(struct device_driver *drv, const char *buf, dev = bus_find_device_by_name(bus, NULL, buf); if (dev && dev->driver == drv) { - if (dev->parent) /* Needed for USB */ + if (dev->parent && dev->bus->need_parent_lock) device_lock(dev->parent); device_release_driver(dev); - if (dev->parent) + if (dev->parent && dev->bus->need_parent_lock) device_unlock(dev->parent); err = count; } @@ -211,12 +211,12 @@ static ssize_t bind_store(struct device_driver *drv, const char *buf, dev = bus_find_device_by_name(bus, NULL, buf); if (dev && dev->driver == NULL && driver_match_device(drv, dev)) { - if (dev->parent) /* Needed for USB */ + if (dev->parent && bus->need_parent_lock) device_lock(dev->parent); device_lock(dev); err = driver_probe_device(drv, dev); device_unlock(dev); - if (dev->parent) + if (dev->parent && bus->need_parent_lock) device_unlock(dev->parent); if (err > 0) { @@ -735,10 +735,10 @@ static int __must_check bus_rescan_devices_helper(struct device *dev, int ret = 0; if (!dev->driver) { - if (dev->parent) /* Needed for USB */ + if (dev->parent && dev->bus->need_parent_lock) device_lock(dev->parent); ret = device_attach(dev); - if (dev->parent) + if (dev->parent && dev->bus->need_parent_lock) device_unlock(dev->parent); } return ret < 0 ? ret : 0; @@ -770,10 +770,10 @@ EXPORT_SYMBOL_GPL(bus_rescan_devices); int device_reprobe(struct device *dev) { if (dev->driver) { - if (dev->parent) /* Needed for USB */ + if (dev->parent && dev->bus->need_parent_lock) device_lock(dev->parent); device_release_driver(dev); - if (dev->parent) + if (dev->parent && dev->bus->need_parent_lock) device_unlock(dev->parent); } return bus_rescan_devices_helper(dev, NULL); diff --git a/drivers/base/dd.c b/drivers/base/dd.c index c9f54089429b..7c09f73b96f3 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -817,13 +817,13 @@ static int __driver_attach(struct device *dev, void *data) return ret; } /* ret > 0 means positive match */ - if (dev->parent) /* Needed for USB */ + if (dev->parent && dev->bus->need_parent_lock) device_lock(dev->parent); device_lock(dev); if (!dev->driver) driver_probe_device(drv, dev); device_unlock(dev); - if (dev->parent) + if (dev->parent && dev->bus->need_parent_lock) device_unlock(dev->parent); return 0; @@ -919,7 +919,7 @@ void device_release_driver_internal(struct device *dev, struct device_driver *drv, struct device *parent) { - if (parent) + if (parent && dev->bus->need_parent_lock) device_lock(parent); device_lock(dev); @@ -927,7 +927,7 @@ void device_release_driver_internal(struct device *dev, __device_release_driver(dev, parent); device_unlock(dev); - if (parent) + if (parent && dev->bus->need_parent_lock) device_unlock(parent); } diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c index 9792cedfc351..e76e95f62f76 100644 --- a/drivers/usb/core/driver.c +++ b/drivers/usb/core/driver.c @@ -1922,4 +1922,5 @@ struct bus_type usb_bus_type = { .name = "usb", .match = usb_device_match, .uevent = usb_uevent, + .need_parent_lock = true, }; diff --git a/include/linux/device.h b/include/linux/device.h index 477956990f5e..beca424395dd 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -98,6 +98,8 @@ extern void bus_remove_file(struct bus_type *, struct bus_attribute *); * @lock_key: Lock class key for use by the lock validator * @force_dma: Assume devices on this bus should be set up by dma_configure() * even if DMA capability is not explicitly described by firmware. + * @need_parent_lock: When probing or removing a device on this bus, the + * device core should lock the device's parent. * * A bus is a channel between the processor and one or more devices. For the * purposes of the device model, all devices are connected via a bus, even if @@ -138,6 +140,7 @@ struct bus_type { struct lock_class_key lock_key; bool force_dma; + bool need_parent_lock; }; extern int __must_check bus_register(struct bus_type *bus);