Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Mon, 24 Jan 2022 17:39:08 +0100
From:   Peter Zijlstra <peterz@infradead.org>
To:     Mathias Nyman <mathias.nyman@linux.intel.com>
Cc:     Greg KH <gregkh@linuxfoundation.org>,
        Dave Hansen <dave.hansen@intel.com>,
        Lu Baolu <baolu.lu@linux.intel.com>, x86@kernel.org,
        linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org,
        Chunfeng Yun <chunfeng.yun@mediatek.com>
Subject: Re: earlyprintk=xdbc seems broken
Message-ID: <Ye7WLM+NyVQlEMXN@hirez.programming.kicks-ass.net>
References: <88f466ff-a065-1e9a-4226-0abe2e71b686@linux.intel.com>
 <972a0e28-ad63-9766-88da-02743f80181b@intel.com>
 <Yao35lElOkwtBYEb@kroah.com>
 <c2b5c9bb-1b75-bf56-3754-b5b18812d65e@linux.intel.com>
 <YbyWuxoBSicFBGuv@hirez.programming.kicks-ass.net>
 <YcGhIm7yqYPk4Nuu@hirez.programming.kicks-ass.net>
 <YeE4rtq6t73OxOi+@hirez.programming.kicks-ass.net>
 <cd534ff9-e500-c7ea-426a-347ac2b0830b@linux.intel.com>
 <YeLxE3zQ7Vexk3gv@hirez.programming.kicks-ass.net>
 <dfb311e3-1a83-31a2-3c82-fd982c0757f6@linux.intel.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <dfb311e3-1a83-31a2-3c82-fd982c0757f6@linux.intel.com>
Precedence: bulk

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.