Revert "driver core: Add deferred_probe attribute to devices in sysfs"

This reverts commit 6751667a.

Rob Herring objected to it, and a replacement for it will be added using
debugfs in the future.

Cc: Ben Hutchings <ben.hutchings@codethink.co.uk>
Reported-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/ABI/testing/sysfs-devices-deferred_probe

-What:		/sys/devices/.../deferred_probe
-Date:		August 2016
-Contact:	Ben Hutchings <ben.hutchings@codethink.co.uk>
-Description:
-		The /sys/devices/.../deferred_probe attribute is
-		present for all devices.  If a driver detects during
-		probing a device that a related device is not yet
-		ready, it may defer probing of the first device.  The
-		kernel will retry probing the first device after any
-		other device is successfully probed.  This attribute
-		reads as 1 if probing of this device is currently
-		deferred, or 0 otherwise.

drivers/base/base.h

@@ -141,8 +141,6 @@ extern void device_unblock_probing(void);
 extern struct kset *devices_kset;
 extern void devices_kset_move_last(struct device *dev);
 
-extern struct device_attribute dev_attr_deferred_probe;
-
 #if defined(CONFIG_MODULES) && defined(CONFIG_SYSFS)
 extern void module_add_driver(struct module *mod, struct device_driver *drv);
 extern void module_remove_driver(struct device_driver *drv);

drivers/base/core.c

@@ -1060,14 +1060,8 @@ static int device_add_attrs(struct device *dev)
 			goto err_remove_dev_groups;
 	}
 
-	error = device_create_file(dev, &dev_attr_deferred_probe);
-	if (error)
-		goto err_remove_online;
-
 	return 0;
 
- err_remove_online:
-	device_remove_file(dev, &dev_attr_online);
  err_remove_dev_groups:
 	device_remove_groups(dev, dev->groups);
  err_remove_type_groups:
@@ -1085,7 +1079,6 @@ 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_deferred_probe);
 	device_remove_file(dev, &dev_attr_online);
 	device_remove_groups(dev, dev->groups);
 

drivers/base/dd.c

@@ -53,19 +53,6 @@ static LIST_HEAD(deferred_probe_pending_list);
 static LIST_HEAD(deferred_probe_active_list);
 static atomic_t deferred_trigger_count = ATOMIC_INIT(0);
 
-static ssize_t deferred_probe_show(struct device *dev,
-				   struct device_attribute *attr, char *buf)
-{
-	bool value;
-
-	mutex_lock(&deferred_probe_mutex);
-	value = !list_empty(&dev->p->deferred_probe);
-	mutex_unlock(&deferred_probe_mutex);
-
-	return sprintf(buf, "%d\n", value);
-}
-DEVICE_ATTR_RO(deferred_probe);
-
 /*
  * In some cases, like suspend to RAM or hibernation, It might be reasonable
  * to prohibit probing of devices as it could be unsafe.