From b6f617df4fa936c1ab1831c2b23563f6c1add6c4 Mon Sep 17 00:00:00 2001 From: Saravana Kannan Date: Tue, 2 Mar 2021 13:11:31 -0800 Subject: [PATCH] driver core: Update device link status properly for device_bind_driver() Device link status was not getting updated correctly when device_bind_driver() is called on a device. This causes a warning[1]. Fix this by updating device links that can be updated and dropping device links that can't be updated to a sensible state. [1] - https://lore.kernel.org/lkml/56f7d032-ba5a-a8c7-23de-2969d98c527e@nvidia.com/ Tested-by: Jon Hunter Signed-off-by: Saravana Kannan Link: https://lore.kernel.org/r/20210302211133.2244281-3-saravanak@google.com Signed-off-by: Greg Kroah-Hartman --- drivers/base/base.h | 1 + drivers/base/core.c | 35 +++++++++++++++++++++++++++++++++++ drivers/base/dd.c | 4 +++- 3 files changed, 39 insertions(+), 1 deletion(-) diff --git a/drivers/base/base.h b/drivers/base/base.h index 52b3d7b75c27..1b44ed588f66 100644 --- a/drivers/base/base.h +++ b/drivers/base/base.h @@ -185,6 +185,7 @@ extern int device_links_read_lock(void); extern void device_links_read_unlock(int idx); extern int device_links_read_lock_held(void); extern int device_links_check_suppliers(struct device *dev); +extern void device_links_force_bind(struct device *dev); extern void device_links_driver_bound(struct device *dev); extern void device_links_driver_cleanup(struct device *dev); extern void device_links_no_driver(struct device *dev); diff --git a/drivers/base/core.c b/drivers/base/core.c index f29839382f81..45c75cc96fdc 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -1153,6 +1153,41 @@ static ssize_t waiting_for_supplier_show(struct device *dev, } static DEVICE_ATTR_RO(waiting_for_supplier); +/** + * device_links_force_bind - Prepares device to be force bound + * @dev: Consumer device. + * + * device_bind_driver() force binds a device to a driver without calling any + * driver probe functions. So the consumer really isn't going to wait for any + * supplier before it's bound to the driver. We still want the device link + * states to be sensible when this happens. + * + * In preparation for device_bind_driver(), this function goes through each + * supplier device links and checks if the supplier is bound. If it is, then + * the device link status is set to CONSUMER_PROBE. Otherwise, the device link + * is dropped. Links without the DL_FLAG_MANAGED flag set are ignored. + */ +void device_links_force_bind(struct device *dev) +{ + struct device_link *link, *ln; + + device_links_write_lock(); + + list_for_each_entry_safe(link, ln, &dev->links.suppliers, c_node) { + if (!(link->flags & DL_FLAG_MANAGED)) + continue; + + if (link->status != DL_STATE_AVAILABLE) { + device_link_drop_managed(link); + continue; + } + WRITE_ONCE(link->status, DL_STATE_CONSUMER_PROBE); + } + dev->links.status = DL_DEV_PROBING; + + device_links_write_unlock(); +} + /** * device_links_driver_bound - Update device links after probing its driver. * @dev: Device to update the links for. diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 83a68e980d04..a09bc09401f9 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -459,8 +459,10 @@ int device_bind_driver(struct device *dev) int ret; ret = driver_sysfs_add(dev); - if (!ret) + if (!ret) { + device_links_force_bind(dev); driver_bound(dev); + } else if (dev->bus) blocking_notifier_call_chain(&dev->bus->p->bus_notifier, BUS_NOTIFY_DRIVER_NOT_BOUND, dev);