On Thu, Jun 14, 2018 at 04:50:49PM +0100, Kieran Bingham wrote: > Hi Geert, > > On 14/06/18 14:48, Geert Uytterhoeven wrote: > > Hi Rob et al. > > > > Recent dtc assumes unit addresses are always hexadecimal (without > > prefix), while the bases of reg property values depend on their > > prefixes, and thus can be either decimal or hexadecimal. > > > > This leads to (with W=1): > > > > Warning (graph_port): video-receiver@70/port@10: graph node unit address error, expected "a" > > Warning (graph_port): video-receiver@70/port@11: graph node unit address error, expected "b" > > > > In this particular case, the unit addresses are (assumed hexadecimal) 10 > > resp. 11, while the reg properties are decimal 10 resp. 11, and thus > > don't match. > > > > This RFC patch series corrects the unit addresses to match the reg > > address values for the DT bindings for adi,adv748x and its users. > > There's at least one other violator (port@10 in > > arch/arm/boot/dts/vf610-zii-dev-rev-c.dts), which I didn't fix. > > > > However, ePAPR v1.1 states: > > > > The unit-address component of the name is specific to the bus type > > on which the node sits. It consists of one or more ASCII characters > > from the set of characters in Table 2-1. The unit-address must match > > the first address specified in the reg property of the node. If the > > node has no reg property, the @ and unit-address must be omitted and > > the node-name alone differentiates the node from other nodes at the > > same level in the tree. The binding for a particular bus may specify > > additional, more specific requirements for the format of reg and the > > unit-address. > > > > i.e. nothing about an hexadecimal address requirement? No, because unit-addresses are bus specific, so in theory a bus could use decimal. However, it's pretty well established practice to use hex. > > Should this series be applied, or should the warnings be ignored, until > > dtc is fixed? > > IMO - the ports are human readable indexes, and not hexadecimal. I'd be > loathed to see these become hex. .. especially if not prefixed by a 0x... I read hex. :) > Otherwise, is '10', Ten, or Sixteen? IMO - no 0x = decimal only. It's hex because *everywhere* else is hex. Having a mixture would just invite more confusion and errors (especially because dtc only checks cases it knows the bus type). For OF graph, I'm not that worried about it because 99% of the users have 10 or less ports/endpoints. > That said - I look up and see "video-receiver@70", which is of course the > hexadecimal I2C address :( It is bad enough that I2C addresses get expressed in both 7 and 8-bits (shifted up 1), using decimal there would be really fun. Rob
