Re: [Bug 219906] New: Kernel Oops in pcie_update_link_speed when hotplugging TB4 dock on x870e / kernel 6.14.0-rc7

Re: [Bug 219906] New: Kernel Oops in pcie_update_link_speed when hotplugging TB4 dock on x870e / kernel 6.14.0-rc7

[Bjorn Helgaas]

On Fri, Mar 21, 2025 at 06:30:40PM +0000, bugzilla-daemon@kernel.org wrote:
> https://bugzilla.kernel.org/show_bug.cgi?id=219906
> 
>             Bug ID: 219906
>            Summary: Kernel Oops in pcie_update_link_speed when hotplugging
>                     TB4 dock on x870e / kernel 6.14.0-rc7

> Created attachment 307878
>   --> https://bugzilla.kernel.org/attachment.cgi?id=307878&action=edit
> dmesg output hotplugging dock
> 
> When connecting a Lenovo TB4 dock (40B0) using the USB4 port of an ASRock x870E
> Nova motherboard, Linux kernel 6.14.0-rc7 will Oops with a NULL pointer
> dereference. 
> 
> This is 100% reproducible on my system and happens immediately when plugging
> the USB4 cable into the docking station. Interestingly, USB devices connected
> to the docking station still work, but displays connected to it will not. Also,
> after the kernel Oops the system is in some corrupted state, as things like
> mkinitcpio will hang at the autodetect hook when enumerating udev devices, and
> when shutting down the system will get stuck indefinitely on hanging
> udev_worker processes.
> 
> When booting the machine while the dock is already attached, the kernel boots
> without any apparent problems, but displays connected to the dock will still
> not show any image. 
> 
> This dock has been working without any issue in combination with a different
> Linux laptop with USB4 and an AMD780M, a MacBook Pro, and a Windows 11 laptop.
> 
> Attached is the dmesg output after hot-plugging the dock.

Do you know whether this is a regression?  Does any kernel work
correctly on the system in question?

Re: [Bug 219906] New: Kernel Oops in pcie_update_link_speed when hotplugging TB4 dock on x870e / kernel 6.14.0-rc7

[Lukas Wunner]

On Fri, Mar 21, 2025 at 02:15:04PM -0500, Bjorn Helgaas wrote:
> On Fri, Mar 21, 2025 at 06:30:40PM +0000, bugzilla-daemon@kernel.org wrote:
> > https://bugzilla.kernel.org/show_bug.cgi?id=219906
> > 
> >             Bug ID: 219906
> >            Summary: Kernel Oops in pcie_update_link_speed when hotplugging
> >                     TB4 dock on x870e / kernel 6.14.0-rc7
> 
> Do you know whether this is a regression?  Does any kernel work
> correctly on the system in question?

This is a regression caused by

    commit 665745f274870c921020f610e2c99a3b1613519b
    Author: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
    Date:   Fri Oct 18 17:47:52 2024 +0300

    PCI/bwctrl: Re-add BW notification portdrv as PCIe BW controller

which went into v6.13-rc1.  It can be overcome by duplicating

    commit 62e4492c3063048a163d238cd1734273f2fc757d
    Author: Andreas Noever <andreas.noever@gmail.com>
    Date:   Mon Jun 9 23:03:32 2014 +0200

    PCI: Prevent NULL dereference during pciehp probe

in the bandwidth controller driver.

I can submit a patch tomorrow unless you or Ilpo beat me to it.
(Sorry, I'm still a little sleep deprived today after OSPM Summit.)

Thanks,

Lukas

Re: [Bug 219906] New: Kernel Oops in pcie_update_link_speed when hotplugging TB4 dock on x870e / kernel 6.14.0-rc7

[Wouter Bijlsma]

I don’t know if this is a kernel regression, the only kernel I have tried before 6.14.0-rc7 was the latest stable kernel (6.13.7) which had the same problem.

There might some interaction with the system BIOS though, which may also be bugged. On an earlier BIOS version I could at least get output on displays connected to the dock, despite getting similar kernel crashes and hanging udev_worker processes. With the new bios I cannot get any display output at all, not even for the UEFI boot screens or the Linux text console.

The dmesg output I posted is when plugging in the dock without any displays connected to it though, so something is already failing independent of any potential other issues related to displays.

-Wouter


> On 21 Mar 2025, at 20:15, Bjorn Helgaas <helgaas@kernel.org> wrote:
> 
> On Fri, Mar 21, 2025 at 06:30:40PM +0000, bugzilla-daemon@kernel.org wrote:
>> https://bugzilla.kernel.org/show_bug.cgi?id=219906
>> 
>>            Bug ID: 219906
>>           Summary: Kernel Oops in pcie_update_link_speed when hotplugging
>>                    TB4 dock on x870e / kernel 6.14.0-rc7
> 
>> Created attachment 307878
>>  --> https://bugzilla.kernel.org/attachment.cgi?id=307878&action=edit
>> dmesg output hotplugging dock
>> 
>> When connecting a Lenovo TB4 dock (40B0) using the USB4 port of an ASRock x870E
>> Nova motherboard, Linux kernel 6.14.0-rc7 will Oops with a NULL pointer
>> dereference.
>> 
>> This is 100% reproducible on my system and happens immediately when plugging
>> the USB4 cable into the docking station. Interestingly, USB devices connected
>> to the docking station still work, but displays connected to it will not. Also,
>> after the kernel Oops the system is in some corrupted state, as things like
>> mkinitcpio will hang at the autodetect hook when enumerating udev devices, and
>> when shutting down the system will get stuck indefinitely on hanging
>> udev_worker processes.
>> 
>> When booting the machine while the dock is already attached, the kernel boots
>> without any apparent problems, but displays connected to the dock will still
>> not show any image.
>> 
>> This dock has been working without any issue in combination with a different
>> Linux laptop with USB4 and an AMD780M, a MacBook Pro, and a Windows 11 laptop.
>> 
>> Attached is the dmesg output after hot-plugging the dock.
> 
> Do you know whether this is a regression?  Does any kernel work
> correctly on the system in question?