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

From: Guenter Roeck

Date: Fri May 08 2026 - 14:16:09 EST


On 5/8/26 11:11, Jihong Min wrote:
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?


How about "default USB_XHCI_PCI" ?

Guenter