On 2018-04-27 09:37, Peter Rosin wrote: > On 2018-04-27 09:11, Andrzej Hajda wrote: >> Hi Peter, >> >> On 27.04.2018 00:31, Peter Rosin wrote: >>> Hi! >>> >>> It was noted by Russel King [1] that bridges (not using components) >>> might disappear unexpectedly if the owner of the bridge was unbound. >>> Jyri Sarha had previously noted the same thing with panels [2]. Jyri >>> came up with using device links to resolve the panel issue, which >>> was also my (independent) reaction to the note from Russel. >>> >>> This series builds up to the addition of that link in the last >>> patch, but in my opinion the other 23 patches do have merit on their >>> own. >>> >>> The last patch needs testing, while the others look trivial. That >>> said, I might have missed some subtlety. >> >> of_node is used as an identifier of the bridge in the kernel. If you >> replace it with device pointer there will be potential problem with >> devices having two or more bridges, how do you differentiate bridges if >> the owner is the same? If I remember correctly current bridge code does >> not allow to have multiple bridges in one device, but that should be >> quite easy to fix if necessary. After this change it will become more >> difficult. > > I don't see how it will be more difficult? > >> Anyway I remember discussion that in DT world bridge should be >> identified rather by of_graph port node, not by parent node as it is >> now. If you want to translate this relation to device owner, you should >> add also port number to have full identification of the bridge, ie pair >> (owner, port_number) would be equivalent of port node. > > You even state the trivial solution here, just add the port/endpoint ID > when/if it is needed. So, what is the significant difference? Or, since this is apparently a rare requirement, you could make the owners that do need it fix it themselves. E.g. by embedding the struct drm_bridge in another struct that contains the needed ID, and use container_of to get to that containing struct with the ID. Cheers, Peter -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
