diff options
Diffstat (limited to 'drivers/base/dd.c')
-rw-r--r-- | drivers/base/dd.c | 79 |
1 files changed, 66 insertions, 13 deletions
diff --git a/drivers/base/dd.c b/drivers/base/dd.c index d76cd97a98b6..a8b258e5407b 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -53,6 +53,19 @@ static LIST_HEAD(deferred_probe_pending_list); static LIST_HEAD(deferred_probe_active_list); static atomic_t deferred_trigger_count = ATOMIC_INIT(0); +static ssize_t deferred_probe_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + bool value; + + mutex_lock(&deferred_probe_mutex); + value = !list_empty(&dev->p->deferred_probe); + mutex_unlock(&deferred_probe_mutex); + + return sprintf(buf, "%d\n", value); +} +DEVICE_ATTR_RO(deferred_probe); + /* * In some cases, like suspend to RAM or hibernation, It might be reasonable * to prohibit probing of devices as it could be unsafe. @@ -244,6 +257,7 @@ static void driver_bound(struct device *dev) __func__, dev_name(dev)); klist_add_tail(&dev->p->knode_driver, &dev->driver->p->klist_devices); + device_links_driver_bound(dev); device_pm_check_callbacks(dev); @@ -338,6 +352,10 @@ static int really_probe(struct device *dev, struct device_driver *drv) return ret; } + ret = device_links_check_suppliers(dev); + if (ret) + return ret; + atomic_inc(&probe_count); pr_debug("bus: '%s': %s: probing driver %s with device %s\n", drv->bus->name, __func__, drv->name, dev_name(dev)); @@ -416,6 +434,7 @@ probe_failed: blocking_notifier_call_chain(&dev->bus->p->bus_notifier, BUS_NOTIFY_DRIVER_NOT_BOUND, dev); pinctrl_bind_failed: + device_links_no_driver(dev); devres_release_all(dev); driver_sysfs_remove(dev); dev->driver = NULL; @@ -508,6 +527,7 @@ int driver_probe_device(struct device_driver *drv, struct device *dev) pr_debug("bus: '%s': %s: matched device %s with driver %s\n", drv->bus->name, __func__, dev_name(dev), drv->name); + pm_runtime_get_suppliers(dev); if (dev->parent) pm_runtime_get_sync(dev->parent); @@ -518,6 +538,7 @@ int driver_probe_device(struct device_driver *drv, struct device *dev) if (dev->parent) pm_runtime_put(dev->parent); + pm_runtime_put_suppliers(dev); return ret; } @@ -772,7 +793,7 @@ EXPORT_SYMBOL_GPL(driver_attach); * __device_release_driver() must be called with @dev lock held. * When called for a USB interface, @dev->parent lock must be held as well. */ -static void __device_release_driver(struct device *dev) +static void __device_release_driver(struct device *dev, struct device *parent) { struct device_driver *drv; @@ -781,7 +802,27 @@ static void __device_release_driver(struct device *dev) if (driver_allows_async_probing(drv)) async_synchronize_full(); + while (device_links_busy(dev)) { + device_unlock(dev); + if (parent) + device_unlock(parent); + + device_links_unbind_consumers(dev); + if (parent) + device_lock(parent); + + device_lock(dev); + /* + * A concurrent invocation of the same function might + * have released the driver successfully while this one + * was waiting, so check for that. + */ + if (dev->driver != drv) + return; + } + pm_runtime_get_sync(dev); + pm_runtime_clean_up_links(dev); driver_sysfs_remove(dev); @@ -796,6 +837,8 @@ static void __device_release_driver(struct device *dev) dev->bus->remove(dev); else if (drv->remove) drv->remove(dev); + + device_links_driver_cleanup(dev); devres_release_all(dev); dev->driver = NULL; dev_set_drvdata(dev, NULL); @@ -812,12 +855,32 @@ static void __device_release_driver(struct device *dev) } } +void device_release_driver_internal(struct device *dev, + struct device_driver *drv, + struct device *parent) +{ + if (parent) + device_lock(parent); + + device_lock(dev); + if (!drv || drv == dev->driver) + __device_release_driver(dev, parent); + + device_unlock(dev); + if (parent) + device_unlock(parent); +} + /** * device_release_driver - manually detach device from driver. * @dev: device. * * Manually detach device from driver. * When called for a USB interface, @dev->parent lock must be held. + * + * If this function is to be called with @dev->parent lock held, ensure that + * the device's consumers are unbound in advance or that their locks can be + * acquired under the @dev->parent lock. */ void device_release_driver(struct device *dev) { @@ -826,9 +889,7 @@ void device_release_driver(struct device *dev) * within their ->remove callback for the same device, they * will deadlock right here. */ - device_lock(dev); - __device_release_driver(dev); - device_unlock(dev); + device_release_driver_internal(dev, NULL, NULL); } EXPORT_SYMBOL_GPL(device_release_driver); @@ -853,15 +914,7 @@ void driver_detach(struct device_driver *drv) dev = dev_prv->device; get_device(dev); spin_unlock(&drv->p->klist_devices.k_lock); - - if (dev->parent) /* Needed for USB */ - device_lock(dev->parent); - device_lock(dev); - if (dev->driver == drv) - __device_release_driver(dev); - device_unlock(dev); - if (dev->parent) - device_unlock(dev->parent); + device_release_driver_internal(dev, drv, dev->parent); put_device(dev); } } |