Hi Nico, Thanks for your email.
Indeed, I'm talking about libpayload's USB stack. There does seem to be a limit as I don't see usbhub.c or generic_hub.c calling any routines beyond enable_port() for the ports beyond the HUB. Enable_port() merely provides power to those ports. It doesn't scan them and then attach them in any way. JP On Thu, Mar 9, 2017 at 5:16 AM, Nico Huber <nico.hu...@secunet.com> wrote: > On 09.03.2017 11:18, Joshua Pincus wrote: > > Hi, > > > > I'm new to coreboot and to this group. As this is my first post, let me > > thank you folks for developing an impressive and incredibly useful > product! > > Hi Joshua, > > > I recently fired up the coreboot USB stack on an x86 development board. > > The USB stack reported back that I have 2 EHCI host controllers on the > > board. Each controller, in turn, has a number of ports. Attached to at > > most 1 of the ports beyond each controller is a USB 2.0 hub. Each hub, > in > > turn, has a number of ports which the coreboot USB stack enables. > > are you talking about libpayload's USB stack? coreboot itself doesn't > have one. > > > > > My issue is this: I see the host controllers get initialized. I see the > > aforementioned hubs get initialized. I see the ports underneath those > hubs > > get enabled. I do not see nor can I find any existing code that scans > and > > attaches the ports associated with those hubs. Consequently, none of the > > devices (aka keyboard, USB stick, etc.) plugged into the ports beyond > those > > hubs are scanned and attached. Put another way, it looks like the USB > > stack, as currently written, only scans and attaches devices at tier 0 > and > > tier 1. Anything beyond the hub is merely enabled. > > > > Am I wrong or missing something? How difficult would it be to continue > the > > process of recursion to subsequent tiers? > > If you are talking about libpayload, there shouldn't be an artificial > limit. Responsible for hub class USB devices is the code in drivers/usb/ > generic_hub.c + drivers/usb/usbhub.c. > > Hope that helps, > Nico > >
-- coreboot mailing list: coreboot@coreboot.org https://www.coreboot.org/mailman/listinfo/coreboot