[REGRESSION 6.14] Some PCI device BARs inacessible

[REGRESSION 6.14] Some PCI device BARs inacessible

[Michał Pecio]

Hi,

This is a heads up that an apparent PCI regression has been reported
and mistakenly assigned to USB in the kernel bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=220016

Visible symptom is missing USB devices, but the whole controller fails
to probe, apparently due to devm_request_mem_region() returning NULL,
see drivers/usb/core/hcd-pci.c and usb_hcd_pci_probe().

Same systems also show a similar failure with some AHCI controller.
It seems specific to particular ASUS AMD motherboards.

Somebody found that disabling CONFIG_PCI_REALLOC_ENABLE_AUTO helps.

That's all I know, reporters can be reached via bugzilla.

Regards,
Michal

Re: [REGRESSION 6.14] Some PCI device BARs inacessible

[Bjorn Helgaas]

[+cc Joe (reporter), Ilpo]
[+bcc Steven (another reporter, bcc since email hasn't been used publicly recently]

On Fri, Apr 18, 2025 at 10:29:26AM +0200, Michał Pecio wrote:
> This is a heads up that an apparent PCI regression has been reported
> and mistakenly assigned to USB in the kernel bugzilla:
> 
> https://bugzilla.kernel.org/show_bug.cgi?id=220016
> 
> Visible symptom is missing USB devices, but the whole controller fails
> to probe, apparently due to devm_request_mem_region() returning NULL,
> see drivers/usb/core/hcd-pci.c and usb_hcd_pci_probe().
> 
> Same systems also show a similar failure with some AHCI controller.
> It seems specific to particular ASUS AMD motherboards.
> 
> Somebody found that disabling CONFIG_PCI_REALLOC_ENABLE_AUTO helps.
> 
> That's all I know, reporters can be reached via bugzilla.

#regzbot link: https://bugzilla.kernel.org/show_bug.cgi?id=220016