Hi Rob, Michael has an issue that means this patch series is not OK in the current form. I will work on a v7 to see if I can resolve the issue. -Frank On 06/20/17 21:57, Michael Ellerman wrote: > Hi Frank, > > frowand.list@xxxxxxxxx writes: >> From: Frank Rowand <frank.rowand@xxxxxxxx> >> >> Remove "phandle", "linux,phandle", and "ibm,phandle" properties from >> the internal device tree. The phandle will still be in the struct >> device_node phandle field and will still be displayed as if it is >> a property in /proc/device_tree. >> >> This is to resolve the issue found by Stephen Boyd [1] when he changed >> the type of struct property.value from void * to const void *. As >> a result of the type change, the overlay code had compile errors >> where the resolver updates phandle values. >> >> [1] http://lkml.iu.edu/hypermail/linux/kernel/1702.1/04160.html >> >> - Add sysfs infrastructure to report np->phandle, as if it was a property. >> - Do not create "phandle" "ibm,phandle", and "linux,phandle" properties >> in the expanded device tree. >> - Remove phandle properties in of_attach_node(), for nodes dynamically >> attached to the live tree. Add the phandle sysfs entry for these nodes. >> - When creating an overlay changeset, duplicate the node phandle in >> __of_node_dup(). >> - Remove no longer needed checks to exclude "phandle" and "linux,phandle" >> properties in several locations. >> - A side effect of these changes is that the obsolete "linux,phandle" and >> "ibm,phandle" properties will no longer appear in /proc/device-tree (they >> will appear as "phandle"). > > Sorry but I don't think that can work for us. > > Our DLPAR (ie. CPU/memory/device hotplug) stuff on PowerVM uses > "ibm,phandle", and it's not the same thing as "phandle" / > "linux,phandle". > > I don't know the code well myself, but the spec (PAPR) says: > > Note: If the “ibm,phandle” property exists, there are two “phandle” > namespaces which must be kept separate. One is that actually used by > the OF client interface, the other is properties in the device tree > making reference to device tree nodes. These requirements are written > to maintain backward compatibility with older FW versions predating > these requirements; if the “ibm,phandle” property is not present, the > OS may assume that any device tree properties which refer to this node > will have a phandle value matching that returned by client interface > services. > > I have systems here that still use "ibm,phandle". I also see at least > some of the userspace code that looks for "ibm,phandle", and nothing > else. > > The note above actually implies that the current Linux code is wrong, > when it uses "ibm,phandle" as the value of np->phandle. > > So sorry that's a big mess, but we can't just rip out those properties. > > I think the minimal change would be to treat "ibm,phandle" like a normal > property, I think that would allow our tools to keep working? > > > The other thing that worries me is that by renaming (effectively) > "linux,phandle" to "phandle", we lose the ability to accurately > regenerate the device tree from /proc/device-tree. In theory it > shouldn't matter, but I worry that in practice something will break. > > What if we just kept a single bit flag somewhere indicating if the name of > the phandle property we found was "phandle" or "linux,phandle", and > create the sysfs phandle using that name? > > cheers > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
