Re: [PATCH v4 1/2] usb: xhci-pci: add AMD Promontory 21 PCI glue

[Jihong Min <hurryman2212@icloud.com>]

>> Something else I was thinking about while reviewing this series.
>>
>> Promontory 21 is only on AMD platforms and AMD platforms are only 
>> x86. I think the Kconfig should be conditional on AMD CPU support 
>> being enabled and X86 architecture so that we don't bloat other 
>> architectures with dead code that will never run.
One related Kconfig question: would it be acceptable to make
USB_XHCI_PCI_PROM21 default y with the X86 && CPU_SUP_AMD dependency?

This would only default-enable the PROM21 xHCI PCI glue. The hwmon driver
would still be controlled separately by SENSORS_PROM21_XHCI and would remain
opt-in, so the undocumented temperature register polling would not be 
enabled
by default.

The concern is that, without default y, distribution configs may miss the
PROM21 PCI glue and then SENSORS_PROM21_XHCI can not bind even if the hwmon
driver itself is enabled or available as a module.

Would you prefer this, or should USB_XHCI_PCI_PROM21 remain explicitly 
enabled
by distributions?

Sincerely,
Jihong Min