Re: [Bug 216859] New: PCI bridge to bus boot hang at enumeration

[Bjorn Helgaas <helgaas@kernel.org>]

[+cc Krzysztof]

On Fri, Jan 06, 2023 at 05:42:33PM +0100, Zeno Davatz wrote:
> On Fri, Dec 30, 2022 at 7:50 PM Bjorn Helgaas <helgaas@kernel.org> wrote:
> > On Wed, Dec 28, 2022 at 12:42:34PM -0600, Bjorn Helgaas wrote:
> > > On Wed, Dec 28, 2022 at 06:42:38PM +0100, Zeno Davatz wrote:
> > > > On Wed, Dec 28, 2022 at 1:02 PM Bjorn Helgaas <helgaas@kernel.org> wrote:
> > > > > On Wed, Dec 28, 2022 at 08:37:52AM +0000, bugzilla-daemon@kernel.org wrote:
> > > > > > https://bugzilla.kernel.org/show_bug.cgi?id=216859
> > > > >
> > > > > >            Summary: PCI bridge to bus boot hang at enumeration
> > > > > >     Kernel Version: 6.1-rc1
> > > > > > ...
> > > > >
> > > > > > With Kernel 6.1-rc1 the enumeration process stopped working for me,
> > > > > > see attachments.
> > > > > >
> > > > > > The enumeration works fine with Kernel 6.0 and below.
> > > > > >
> > > > > > Same problem still exists with v6.1. and v6.2.-rc1
> > > > >
> > > > > Thank you very much for your report, Zeno!
> > > > >
> > > > > v6.0 works, v6.1-rc1 fails.  Would you mind booting v6.1-rc1 with the
> > > > > "ignore_loglevel initcall_debug" kernel parameters and taking a photo
> > > > > when it hangs?
> > > >
> > > > I will try this after Januar 7th 2023.
> 
> I updated the issue:
> 
> https://bugzilla.kernel.org/show_bug.cgi?id=216859
> 
> I booted with the option: "ignore_loglevel initcall_debug"

Thanks!  There's so much pcie output in that picture that we can't see
any of the initcall logging.  Can you capture another movie, but use
kernel parameters like "ignore_loglevel initcall_debug boot_delay=100"
to slow things down?  The full-speed boot is too fast for the camera
to capture all the output.  You can do this on any convenient kernel
that hangs.

There might be more we can do with the bisection, too, but I don't
have any suggestions for that yet.  Maybe Krzysztof does.

Bjorn