On Sat, Dec 13, 2014 at 5:46 PM, Sebastian Reichel <sre@xxxxxxxxxx> wrote: > Hi, > > On Fri, Dec 12, 2014 at 11:59:20AM +0000, Grant Likely wrote: >> [...] >> > --- a/Documentation/devicetree/bindings/serial/of-serial.txt >> > +++ b/Documentation/devicetree/bindings/serial/of-serial.txt >> > @@ -39,6 +39,10 @@ Optional properties: >> > driver is allowed to detect support for the capability even without this >> > property. >> > >> > +Optional child node: >> > +- a platform device listed as a child node will be probed and >> > + powered-on whenever the tty is in use (open). >> > + >> >> The biggest concern I have is what happens to nodes that already have >> child devices that /don't/ match this use case? It is possible that some >> UART nodes already have a child node used to store other data. There are >> two ways to handle this; 1) add a new bool property that indicates the >> child nodes are tty slave devices, or 2) Make each uart driver >> explicitly enable the feature so that driver authors can check if it is >> a problem for that device. I personally would suggest #1 because then it >> can be enabled in generic code. > > maybe simple depend on the compatible value? If the UART node has > child nodes to store other random data it should not have a > compatible value? That's not a given. It is entirely possible that drivers have used compatible in the child nodes. However, I may be stirring up trouble for nothing. We could enable it for all child nodes that have a compatible value, and then blacklist any parent nodes that want to use a different behaviour. If someone complains then we will fix it. g. -- 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
