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driver core: Add waiting_for_supplier sysfs file for devices

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This would be useful to check if a device is not probing because it's
waiting for a supplier to be added and then linked to before it can
probe.

To reduce sysfs clutter, this file is added only if it can ever be 1.
So, if fw_devlink is disabled or set to permissive, this file is not
added. Also, this file is removed once the device probes as it's no
longer relevant.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20200521191800.136035-4-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Saravana Kannan
2020-05-21 12:18:00 -07:00
committed by Greg Kroah-Hartman
parent 8fd456ec0c
commit da6d647598
2 changed files with 43 additions and 0 deletions
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26
drivers/base/core.c
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@@ -1041,6 +1041,22 @@ static void device_link_drop_managed(struct device_link *link)
kref_put(&link->kref, __device_link_del);
}
static ssize_t waiting_for_supplier_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
bool val;
device_lock(dev);
mutex_lock(&wfs_lock);
val = !list_empty(&dev->links.needs_suppliers)
&& dev->links.need_for_probe;
mutex_unlock(&wfs_lock);
device_unlock(dev);
return sprintf(buf, "%u\n", val);
}
static DEVICE_ATTR_RO(waiting_for_supplier);
/**
* device_links_driver_bound - Update device links after probing its driver.
* @dev: Device to update the links for.
@@ -1065,6 +1081,7 @@ void device_links_driver_bound(struct device *dev)
mutex_lock(&wfs_lock);
list_del_init(&dev->links.needs_suppliers);
mutex_unlock(&wfs_lock);
device_remove_file(dev, &dev_attr_waiting_for_supplier);
device_links_write_lock();
@@ -2144,8 +2161,16 @@ static int device_add_attrs(struct device *dev)
goto err_remove_dev_groups;
}
if (fw_devlink_flags && !fw_devlink_is_permissive()) {
error = device_create_file(dev, &dev_attr_waiting_for_supplier);
if (error)
goto err_remove_dev_online;
}
return 0;
err_remove_dev_online:
device_remove_file(dev, &dev_attr_online);
err_remove_dev_groups:
device_remove_groups(dev, dev->groups);
err_remove_type_groups:
@@ -2163,6 +2188,7 @@ static void device_remove_attrs(struct device *dev)
struct class *class = dev->class;
const struct device_type *type = dev->type;
device_remove_file(dev, &dev_attr_waiting_for_supplier);
device_remove_file(dev, &dev_attr_online);
device_remove_groups(dev, dev->groups);