From: Saravana Kannan <saravanak@xxxxxxxxxx> commit 21eb93f432b1a785df193df1a56a59e9eb3a985f upstream. The initial patch that added sync_state() support didn't handle the case where a supplier has no consumers. This was because when a device is successfully bound with a driver, only its suppliers were checked to see if they are eligible to get a sync_state(). This is not sufficient for devices that have no consumers but still need to do device state clean up. So fix this. Fixes: fc5a251d0fd7ca90 (driver core: Add sync_state driver/bus callback) Signed-off-by: Saravana Kannan <saravanak@xxxxxxxxxx> Cc: stable <stable@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20200221080510.197337-2-saravanak@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/base/core.c | 23 +++++++++++++++++------ 1 file changed, 17 insertions(+), 6 deletions(-) --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -745,25 +745,31 @@ static void __device_links_queue_sync_st /** * device_links_flush_sync_list - Call sync_state() on a list of devices * @list: List of devices to call sync_state() on + * @dont_lock_dev: Device for which lock is already held by the caller * * Calls sync_state() on all the devices that have been queued for it. This - * function is used in conjunction with __device_links_queue_sync_state(). + * function is used in conjunction with __device_links_queue_sync_state(). The + * @dont_lock_dev parameter is useful when this function is called from a + * context where a device lock is already held. */ -static void device_links_flush_sync_list(struct list_head *list) +static void device_links_flush_sync_list(struct list_head *list, + struct device *dont_lock_dev) { struct device *dev, *tmp; list_for_each_entry_safe(dev, tmp, list, links.defer_sync) { list_del_init(&dev->links.defer_sync); - device_lock(dev); + if (dev != dont_lock_dev) + device_lock(dev); if (dev->bus->sync_state) dev->bus->sync_state(dev); else if (dev->driver && dev->driver->sync_state) dev->driver->sync_state(dev); - device_unlock(dev); + if (dev != dont_lock_dev) + device_unlock(dev); put_device(dev); } @@ -801,7 +807,7 @@ void device_links_supplier_sync_state_re out: device_links_write_unlock(); - device_links_flush_sync_list(&sync_list); + device_links_flush_sync_list(&sync_list, NULL); } static int sync_state_resume_initcall(void) @@ -865,6 +871,11 @@ void device_links_driver_bound(struct de driver_deferred_probe_add(link->consumer); } + if (defer_sync_state_count) + __device_links_supplier_defer_sync(dev); + else + __device_links_queue_sync_state(dev, &sync_list); + list_for_each_entry(link, &dev->links.suppliers, c_node) { if (!(link->flags & DL_FLAG_MANAGED)) continue; @@ -883,7 +894,7 @@ void device_links_driver_bound(struct de device_links_write_unlock(); - device_links_flush_sync_list(&sync_list); + device_links_flush_sync_list(&sync_list, dev); } static void device_link_drop_managed(struct device_link *link)
