diff options
Diffstat (limited to 'drivers/base/core.c')
| -rw-r--r-- | drivers/base/core.c | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c index b3896da73b3d..acbf0b1414ab 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -46,6 +46,8 @@ early_param("sysfs.deprecated", sysfs_deprecated_setup); /* Device links support. */ static LIST_HEAD(wait_for_suppliers); static DEFINE_MUTEX(wfs_lock); +static LIST_HEAD(deferred_sync); +static unsigned int defer_sync_state_count = 1; #ifdef CONFIG_SRCU static DEFINE_MUTEX(device_links_lock); @@ -648,6 +650,69 @@ int device_links_check_suppliers(struct device *dev) return ret; } +static void __device_links_supplier_sync_state(struct device *dev) +{ + struct device_link *link; + + if (dev->state_synced) + return; + + list_for_each_entry(link, &dev->links.consumers, s_node) { + if (!(link->flags & DL_FLAG_MANAGED)) + continue; + if (link->status != DL_STATE_ACTIVE) + return; + } + + if (dev->bus->sync_state) + dev->bus->sync_state(dev); + else if (dev->driver && dev->driver->sync_state) + dev->driver->sync_state(dev); + + dev->state_synced = true; +} + +void device_links_supplier_sync_state_pause(void) +{ + device_links_write_lock(); + defer_sync_state_count++; + device_links_write_unlock(); +} + +void device_links_supplier_sync_state_resume(void) +{ + struct device *dev, *tmp; + + device_links_write_lock(); + if (!defer_sync_state_count) { + WARN(true, "Unmatched sync_state pause/resume!"); + goto out; + } + defer_sync_state_count--; + if (defer_sync_state_count) + goto out; + + list_for_each_entry_safe(dev, tmp, &deferred_sync, links.defer_sync) { + __device_links_supplier_sync_state(dev); + list_del_init(&dev->links.defer_sync); + } +out: + device_links_write_unlock(); +} + +static int sync_state_resume_initcall(void) +{ + device_links_supplier_sync_state_resume(); + return 0; +} +late_initcall(sync_state_resume_initcall); + +static void __device_links_supplier_defer_sync(struct device *sup) +{ + if (list_empty(&sup->links.defer_sync)) + list_add_tail(&sup->links.defer_sync, &deferred_sync); +} + /** * device_links_driver_bound - Update device links after probing its driver. * @dev: Device to update the links for. @@ -692,6 +757,11 @@ void device_links_driver_bound(struct device *dev) WARN_ON(link->status != DL_STATE_CONSUMER_PROBE); WRITE_ONCE(link->status, DL_STATE_ACTIVE); + + if (defer_sync_state_count) + __device_links_supplier_defer_sync(link->supplier); + else + __device_links_supplier_sync_state(link->supplier); } dev->links.status = DL_DEV_DRIVER_BOUND; @@ -808,6 +878,7 @@ void device_links_driver_cleanup(struct device *dev) WRITE_ONCE(link->status, DL_STATE_DORMANT); } + list_del_init(&dev->links.defer_sync); __device_links_no_driver(dev); device_links_write_unlock(); @@ -1782,6 +1853,7 @@ void device_initialize(struct device *dev) INIT_LIST_HEAD(&dev->links.consumers); INIT_LIST_HEAD(&dev->links.suppliers); INIT_LIST_HEAD(&dev->links.needs_suppliers); + INIT_LIST_HEAD(&dev->links.defer_sync); dev->links.status = DL_DEV_NO_DRIVER; } EXPORT_SYMBOL_GPL(device_initialize); |