Hi Alan, On Thu, Oct 12, 2017 at 11:17 PM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > On Thu, 12 Oct 2017, Martin Blumenstingl wrote: > >> I haven't tested the described use-case. however, this patch is not >> supposed to change the binding for actual devices. >> USB device numbering starts at 1, while 0 is reserved for the root-hub >> (at least from what I know). > > Actually 1 is reserved for the root hub. External devices are numbered > starting from 2. (We can't use 0 for the root hub because, as you > said, USB device numbering starts at 1!) I just had a look at lsusb again: $ lsusb -t /: Bus 04.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/2p, 5000M however, for the devicetree bindings the devices are supposed to use 1-31: [0] Alan: just to make sure I understood you correctly: do you agree with this patch? > Alan Stern > >> before this patch there was no way to >> describe the root-hub via .dts. this however is required for some >> platforms that need to set up a PHY for each port on the root-hub >> (Amlogic Meson GXL platform is one example: there are two ports >> enabled on dwc3's root-hub with 2x USB2 and 1x USB3 PHYs) - so this >> patch uses a similar binding as we already have (to describe the >> devices) to describe the root-hub >> >> >> Regards, >> Martin >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-usb" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> >> > Regards, Martin [0] http://elixir.free-electrons.com/linux/v4.14-rc4/source/Documentation/devicetree/bindings/usb/usb-device.txt -- 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
