Re: Suspend regression in v6.18-rc1

["Neronin, Niklas" <niklas.neronin@linux.intel.com>]

On 15/10/2025 4.22, Phillip Susi wrote:
> I have a suspend regression in v6.18-rc1 that results in this in my
> dmesg when I try to suspend:
> 
> [   36.739259] Freezing remaining freezable tasks
> [   36.740378] Freezing remaining freezable tasks completed (elapsed 0.001 seconds)
> [   36.740414] printk: Suspending console(s) (use no_console_suspend to debug)
> [   36.783363] xhci_hcd 0000:51:00.0: Root hub is not suspended
> [   36.783366] xhci_hcd 0000:51:00.0: PM: pci_pm_suspend(): hcd_pci_suspend [usbcore] returns -16
> [   36.783378] xhci_hcd 0000:51:00.0: PM: dpm_run_callback(): pci_pm_suspend returns -16
> [   36.783383] xhci_hcd 0000:51:00.0: PM: failed to suspend async: error
> -16
> 
> I have bisected it to this commit:
> 
> commit 719de070f764e079cdcb4ddeeb5b19b3ddddf9c1 (HEAD)
> Author: Niklas Neronin <niklas.neronin@linux.intel.com>
> Date:   Thu Sep 18 00:07:22 2025 +0300
> 
>     usb: xhci-pci: add support for hosts with zero USB3 ports
>     
>     Add xhci support for PCI hosts that have zero USB3 ports.
>     Avoid creating a shared Host Controller Driver (HCD) when there is only
>     one root hub. Additionally, all references to 'xhci->shared_hcd' are now
>     checked before use.
>     
>     Only xhci-pci.c requires modification to accommodate this change, as the
>     xhci core already supports configurations with zero USB3 ports. This
>     capability was introduced when xHCI Platform and MediaTek added support
>     for zero USB3 ports.
>     
>     Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220181
>     Tested-by: Nick Nielsen <nick.kainielsen@free.fr>
>     Tested-by: grm1 <grm1@mailbox.org>
>     Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com>
>     Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
>     Link: https://lore.kernel.org/r/20250917210726.97100-4-mathias.nyman@linux.intel.com
>     Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> 
> It sounds like it may be related to these errors that I have had on this
> system since I built it last year:
> 
> Oct 14 20:55:36 faldara kernel: hub 10-0:1.0: USB hub found
> Oct 14 20:55:36 faldara kernel: hub 10-0:1.0: config failed, hub doesn't
> have any ports! (err -19)
> 
> I believe this system has a usb hub with "zero ports" that this patch
> was meant to fix, but up until now, has only resulted in this beign
> dmesg error.  I no longer see this error after this commit.
> 
> This is an ASrock 650E Taichi Lite motherboard I built last year.
> 
> What additional information can I provide?

Hi,

Thank you for reporting.

I believe this might be related to the issue in this thread:
https://lore.kernel.org/linux-usb/CABpa4MA9unucCoKtSdzJyOLjHNVy+Cwgz5AnAxPkKw6vuox1Nw@mail.gmail.com/

The specific fix:
https://lore.kernel.org/linux-usb/20251013100424.42d5b9d2.michal.pecio@gmail.com/

Best Regards,
Niklas