Re: [PATCH] nvdimm: nvdimm_bus_register: Avoid adding device to the unregistered bus

[Dan Williams <dan.j.williams@intel.com>]

lizhijian@fujitsu.com wrote:
[..]
> > Now I do think it would be a good idea to fail device_add() if the bus
> > is not registered,
> 
> BTW, below line 369: device_add() didn't fail in practical.
> 

I think that's ok because the device gets added, but never probed due to
this part of that commit I referenced:

@@ -503,20 +517,21 @@ int bus_add_device(struct device *dev)
  */
 void bus_probe_device(struct device *dev)
 {
-       struct bus_type *bus = dev->bus;
+       struct subsys_private *sp = bus_to_subsys(dev->bus);
        struct subsys_interface *sif;
 
-       if (!bus)
+       if (!sp)
                return;
 

...so it does what you want which is disable the libnvdimm subsystem
from binding to any devices without crashing.