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driver core: Update device link status properly for device_bind_driver()

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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 <jonathanh@nvidia.com>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20210302211133.2244281-3-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Saravana Kannan 2021-03-02 13:11:31 -08:00 committed by Greg Kroah-Hartman
parent f2db85b64f
commit b6f617df4f
3 changed files with 39 additions and 1 deletions
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1
drivers/base/base.h
View File

@ -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);

35
drivers/base/core.c
View File

@ -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.

4
drivers/base/dd.c
View File

@ -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);