diff --git a/drivers/base/base.h b/drivers/base/base.h index 21c7d244f8aa..866b2beb6baa 100644 --- a/drivers/base/base.h +++ b/drivers/base/base.h @@ -156,6 +156,7 @@ struct kobject *virtual_device_parent(void); int bus_add_device(struct device *dev); void bus_probe_device(struct device *dev); +void bus_probe_device_deferred(struct device *dev); void bus_remove_device(struct device *dev); void bus_notify(struct device *dev, enum bus_notifier_event value); bool bus_is_registered(const struct bus_type *bus); diff --git a/drivers/base/bus.c b/drivers/base/bus.c index 18f12c6f910a..f8759d5c9056 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -606,13 +606,7 @@ int bus_add_device(struct device *dev) return error; } -/** - * bus_probe_device - probe drivers for a new device - * @dev: device to probe - * - * - Automatically probe for a driver if the bus allows it. - */ -void bus_probe_device(struct device *dev) +static void __bus_probe_device(struct device *dev) { struct subsys_private *sp = bus_to_subsys(dev->bus); struct subsys_interface *sif; @@ -630,6 +624,26 @@ void bus_probe_device(struct device *dev) subsys_put(sp); } +/** + * bus_probe_device - probe drivers for a new device + * @dev: device to probe + * + * - Automatically probe for a driver if the bus allows it. + */ +void bus_probe_device(struct device *dev) +{ + __bus_probe_device(dev); +} + +void bus_probe_device_deferred(struct device *dev) +{ + if (dev->type && dev->type->need_parent_lock) + device_lock(dev->parent); + __bus_probe_device(dev); + if (dev->type && dev->type->need_parent_lock) + device_unlock(dev->parent); +} + /** * bus_remove_device - remove device from bus * @dev: device to be removed @@ -857,10 +871,10 @@ static int __must_check bus_rescan_devices_helper(struct device *dev, int ret = 0; if (!dev->driver) { - if (dev->parent && dev->bus->need_parent_lock) + if (dev->type && dev->type->need_parent_lock) device_lock(dev->parent); ret = device_attach(dev); - if (dev->parent && dev->bus->need_parent_lock) + if (dev->type && dev->type->need_parent_lock) device_unlock(dev->parent); } return ret < 0 ? ret : 0; diff --git a/drivers/base/dd.c b/drivers/base/dd.c index f6525a7ee8c5..52123251965d 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -86,8 +86,9 @@ static void deferred_probe_work_func(struct work_struct *work) /* * This block processes every device in the deferred 'active' list. * Each device is removed from the active list and passed to - * bus_probe_device() to re-attempt the probe. The loop continues - * until every device in the active list is removed and retried. + * bus_probe_device_deferred() to re-attempt the probe. The loop + * continues until every device in the active list is removed and + * retried. * * Note: Once the device is removed from the list and the mutex is * released, it is possible for the device get freed by another thread @@ -121,7 +122,7 @@ static void deferred_probe_work_func(struct work_struct *work) device_pm_move_to_tail(dev); dev_dbg(dev, "Retrying from deferred list\n"); - bus_probe_device(dev); + bus_probe_device_deferred(dev); mutex_lock(&deferred_probe_mutex); put_device(dev); @@ -1029,6 +1030,38 @@ static int __device_attach_driver(struct device_driver *drv, void *_data) return ret == 0; } +/* + * __device_driver_lock - acquire locks needed to manipulate dev->drv + * @dev: Device we will update driver info for + * @parent: Parent device. Needed if the device type requires parent lock + * + * This function will take the required locks for manipulating dev->drv. + * Normally this will just be the @dev lock, but when called for a USB + * interface, @parent lock will be held as well. + */ +static void __device_driver_lock(struct device *dev, struct device *parent) +{ + if (dev->type && dev->type->need_parent_lock && parent) + device_lock(parent); + device_lock(dev); +} + +/* + * __device_driver_unlock - release locks needed to manipulate dev->drv + * @dev: Device we will update driver info for + * @parent: Parent device. Needed if the device type requires parent lock + * + * This function will release the required locks for manipulating dev->drv. + * Normally this will just be the @dev lock, but when called for a + * USB interface, @parent lock will be released as well. + */ +static void __device_driver_unlock(struct device *dev, struct device *parent) +{ + device_unlock(dev); + if (dev->type && dev->type->need_parent_lock && parent) + device_unlock(parent); +} + static void __device_attach_async_helper(void *_dev, async_cookie_t cookie) { struct device *dev = _dev; @@ -1038,7 +1071,7 @@ static void __device_attach_async_helper(void *_dev, async_cookie_t cookie) .want_async = true, }; - device_lock(dev); + __device_driver_lock(dev, dev->parent); /* * Check if device has already been removed or claimed. This may @@ -1060,7 +1093,7 @@ static void __device_attach_async_helper(void *_dev, async_cookie_t cookie) if (dev->parent) pm_runtime_put(dev->parent); out_unlock: - device_unlock(dev); + __device_driver_unlock(dev, dev->parent); put_device(dev); } @@ -1117,8 +1150,11 @@ static int __device_attach(struct device *dev, bool allow_async) } out_unlock: device_unlock(dev); - if (async) - async_schedule_dev(__device_attach_async_helper, dev); + if (async && !async_schedule_dev_nocall(__device_attach_async_helper, dev)) { + put_device(dev); + ret = 2; /* retry synchronously */ + } + return ret; } @@ -1145,48 +1181,20 @@ EXPORT_SYMBOL_GPL(device_attach); void device_initial_probe(struct device *dev) { struct subsys_private *sp = bus_to_subsys(dev->bus); + int ret; if (!sp) return; - if (sp->drivers_autoprobe) - __device_attach(dev, true); + if (sp->drivers_autoprobe) { + ret = __device_attach(dev, true); + if (ret == 2) + __device_attach(dev, false); + } subsys_put(sp); } -/* - * __device_driver_lock - acquire locks needed to manipulate dev->drv - * @dev: Device we will update driver info for - * @parent: Parent device. Needed if the bus requires parent lock - * - * This function will take the required locks for manipulating dev->drv. - * Normally this will just be the @dev lock, but when called for a USB - * interface, @parent lock will be held as well. - */ -static void __device_driver_lock(struct device *dev, struct device *parent) -{ - if (parent && dev->bus->need_parent_lock) - device_lock(parent); - device_lock(dev); -} - -/* - * __device_driver_unlock - release locks needed to manipulate dev->drv - * @dev: Device we will update driver info for - * @parent: Parent device. Needed if the bus requires parent lock - * - * This function will release the required locks for manipulating dev->drv. - * Normally this will just be the @dev lock, but when called for a - * USB interface, @parent lock will be released as well. - */ -static void __device_driver_unlock(struct device *dev, struct device *parent) -{ - device_unlock(dev); - if (parent && dev->bus->need_parent_lock) - device_unlock(parent); -} - /** * device_driver_attach - attach a specific driver to a specific device * @drv: Driver to attach diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c index a086b0253691..d3a61ebc6afb 100644 --- a/drivers/usb/core/driver.c +++ b/drivers/usb/core/driver.c @@ -2082,5 +2082,4 @@ const struct bus_type usb_bus_type = { .name = "usb", .match = usb_device_match, .uevent = usb_uevent, - .need_parent_lock = true, }; diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c index 8c4f97c6e9f9..a738d03c23ea 100644 --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -1922,6 +1922,7 @@ const struct device_type usb_if_device_type = { .name = "usb_interface", .release = usb_release_interface, .uevent = usb_if_uevent, + .need_parent_lock = true, }; static struct usb_interface_assoc_descriptor *find_iad(struct usb_device *dev, diff --git a/include/linux/device.h b/include/linux/device.h index 879eb758b5ee..429e39f647cf 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -83,6 +83,10 @@ int subsys_virtual_register(const struct bus_type *subsys, * information, equivalent to the kobj_type of a kobject. * If "name" is specified, the uevent will contain it in * the DEVTYPE variable. + * + * @need_parent_lock: When probing or removing a device of this type, + * driver core should lock the device's parent. Note that + * the device must hold a reference to its parent. */ struct device_type { const char *name; @@ -93,6 +97,7 @@ struct device_type { void (*release)(struct device *dev); const struct dev_pm_ops *pm; + bool need_parent_lock; }; /** diff --git a/include/linux/device/bus.h b/include/linux/device/bus.h index 89e156b9acb5..9ef7538a9a7f 100644 --- a/include/linux/device/bus.h +++ b/include/linux/device/bus.h @@ -68,8 +68,6 @@ struct fwnode_handle; * @driver_override: Set to true if this bus supports the driver_override * mechanism, which allows userspace to force a specific * driver to bind to a device via a sysfs attribute. - * @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 @@ -110,7 +108,6 @@ struct bus_type { const struct dev_pm_ops *pm; bool driver_override; - bool need_parent_lock; }; int __must_check companion_bus_register(const struct bus_type *bus);