Re: earlyprintk=xdbc seems broken

From: Peter Zijlstra
Date: Mon Jan 24 2022 - 11:39:20 EST


On Mon, Jan 24, 2022 at 04:55:22PM +0200, Mathias Nyman wrote:
>
> > [ 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?

Very quick testing says it don't work.. but I'll try again later, need
to go cook dinner now.