Re: earlyprintk=xdbc seems broken

From: Mathias Nyman
Date: Mon Jan 24 2022 - 09:53:57 EST



> [ 0.000000] xhci_dbc:early_xdbc_parse_parameter: dbgp_num: 0
> [ 4.984106] xhci_dbc:xdbc_start: waiting for connection timed out, DCPORTSC:0xa0
> [ 9.946159] xhci_dbc:xdbc_start: waiting for connection timed out, DCPORTSC:0xa0
> [ 9.946163] xhci_dbc:early_xdbc_setup_hardware: failed to setup the connection to host
>
> [ 12.818364] xhci_hcd 0000:00:0d.0: xHCI Host Controller
> [ 12.818373] xhci_hcd 0000:00:0d.0: new USB bus registered, assigned bus number 1
> [ 12.820360] xhci_hcd 0000:00:0d.0: xHCI Host Controller
> [ 12.820363] xhci_hcd 0000:00:0d.0: new USB bus registered, assigned bus number 2
> [ 12.821036] xhci_hcd 0000:00:14.0: xHCI Host Controller
> [ 12.821040] xhci_hcd 0000:00:14.0: new USB bus registered, assigned bus number 3
> [ 12.823451] xhci_hcd 0000:00:14.0: xHCI Host Controller
> [ 12.823453] xhci_hcd 0000:00:14.0: new USB bus registered, assigned bus number 4
> [ 17.115089] usb usb4-port4: Cannot enable. Maybe the USB cable is bad?
> [ 17.115163] usb usb4-port4: config error

Ok, I see it now.
Your setup has two xhci controllers, earlypringk=dbc enables dbc on the first xhci
it finds, which would be at 0000:00:0d.0.
Your cable is connected to the second xhci host at 0000:00:14.0

does using "earlyprintk=xdbc1" work?

Thanks
-Mathias