Re: [gentoo-user] USB-C PD delivery & Lenovo USB-C hub.

[Dom Rodriguez]

On this date - Sun, Sep 22, 2019 at 07:10:28PM +0100, Dom Rodriguez wrote:
> Hello,
>
> On this date - Sun, Sep 22, 2019 at 06:43:50PM +0100, Mick wrote:
> > On Sunday, 22 September 2019 18:06:50 BST Dom Rodriguez wrote:
> > > ... Of course, it _would_ help, if I had provided the link to the hub
> > > itself!
> > >
> > > https://www.amazon.co.uk/gp/product/B07919ZNB4
> > >
> > > :)
> > >
> > > On this date - Sun, Sep 22, 2019 at 06:01:42PM +0100, Dom Rodriguez wrote:
> > > > Hello,
> > > >
> > > > I've got an Lenovo Thinkpad X270 laptop, with USB-C support. I ordered an
> > > > Lenovo USB-C hub from Amazon the other day, and it arrived today. It [the
> > > > hub] is recognised by the kernel for USB, but not for power delivery
> > > > (PD), via ACPI.
> > > >
> > > > Oddly enough, when I plug the USB-C cable from the mains adapter directly
> > > > to the USB-C port, ACPI recognises it fine - so I've narrowed it down to
> > > > a driver issue.
> >
> > I assume you have enabled the USB-C drivers in the kernel and also PCI
> > hotplug?
> >
> > https://wiki.gentoo.org/wiki/USB/Guide#USB_Type-C_and_Thunderbolt
> >
> >
> > > > I've tried using the hub on my Thinkpad 13" on both Windows and Linux
> > > > (Arch, specifically; Gentoo isn't on there at the moment.), and its
> > > > recognised fine. Therefore I do not believe the hub *itself* is faulty.
> > > >
> > > > In terms of diagnostic information, I'm not sure where to start, so if
> > > > anyone needs certain information to help with the issue, please let me
> > > > know, and I'll do my best to email it.
> > > >
> > > > I'm running gentoo-sources-5.3.1 for the kernel.
> > > >
> > > > Any ideas? Thanks :-)
> >
> > I don't have such a device to advise on the specifics, but look at dmesg,
> > lspci -knn, lsusb to see if the device is recognised, or if any errors on
> > missing components are reported.
> > --
> > Regards,
> > Mick
>
> Yeah, I've enabled the USB-C drivers in the kernel and enabled PCI hotplug as
> well.
>
> The device isn't recognised in `lspci` or `lsusb`. `lshw` on the other hand
> reports that 'pci:0', is unclaimed. "pci:1" appears to be the main PCI bridge
> for the laptop. Could well be that "pci:0" is the hub..
>
> As far as I can see in `dmesg`, nothing there is reported either.
>
> A rather odd issue.

Alright, I've managed to isolate the issue to the `tps6598.ko' USB-C PD kernel
module.

I've reached out to the manufacturer of the hub to see if they can advise, but
for now, knowing the problem kernel module has definitely helped getting close
to solving the problem.

-- 
Sincerely,
Dom Rodriguez (shymega).