Suspend regression in v6.18-rc1

Suspend regression in v6.18-rc1

[Phillip Susi]

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?

Re: Suspend regression in v6.18-rc1

[Neronin, Niklas]

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

Re: Suspend regression in v6.18-rc1

[Phillip Susi]

"Neronin, Niklas" <niklas.neronin@linux.intel.com> writes:

>
> 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/

That fixed it, thanks.  It didn't sound related at first but after
reviewing the patch, it started to make sense.