Re: [REGRESSION 5.0.8] Dell thunderbolt dock broken (xhci_hcd and thunderbolt)

Mika Westerberg
2019-04-29T20:36:36Z

On Mon, Apr 29, 2019 at 11:13:47PM +0300, Mika Westerberg wrote:
> On Mon, Apr 29, 2019 at 10:03:00PM +0200, Michael Hirmke wrote:
> > Hi all,
> >
> > >On Mon, Apr 29, 2019 at 09:47:15PM +0200, Takashi Iwai wrote:
> > >> Hi,
> >
> > >Hi,
> >
> > >> we've got a regression report wrt xhci_hcd and thunderbolt on a Dell
> > >> machine. 5.0.7 is confirmed to work, so it must be a regression
> > >> introduced by 5.0.8.
> > >>
> > >> The details are found in openSUSE Bugzilla entry:
> > >> https://bugzilla.opensuse.org/show_bug.cgi?id=1132943
> > >>
> > [...]
> > >>
> > >> I blindly suspected the commit 3943af9d01e9 and asked for a reverted
> > >> kernel, but in vain. And now it was confirmed that the problem is
> > >> present with the latest 5.1-rc, too.
> > >>
> > >> I put some people who might have interest and the reporter (Michael)
> > >> to Cc. If anyone has an idea, feel free to join to the Bugzilla, or
> > >> let me know if any help needed from the distro side.
> >
> > >Since it exists in 5.1-rcX also it would be good if someone
> > >who see the problem (Michael?) could bisect it.
> >
> > I know the meaning of bisecting, but I'm not really a developer, so I am
> > probably not able to interpret the results.
>
> No worries.
>
> I'm adding Christian who reported similar (same?) problem last week.
> Christian, this seems to exist in v5.1-rc6 at least. Can you try to
> bisect it on your side?
>
> I also have XPS 9370 but not that particular dock. I will check tomorrow
> if I can reproduce it as well.

There aren't too many changes between 5.0.7 and 5.0.8 that touch
PCI/ACPI. This is just a shot in the dark but could you try to revert:

https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git/commit/?h=linux-5.0.y&id=da6a87fb0ad43ae811519d2e0aa325c7f792b13a

and see if it makes any difference?