Re: [PATCH v3 RESEND] PCI: Introduce Cray ClusterStor E1000 NVMe slot LED driver

Tony Hutter
2025-05-20T21:35:25Z

Hi Pavel

> We have LED subsystem.
>
> And this should use it.

This came up in an earlier discussion, and I touched on it in my changelog:

- Kept the /sys/bus/pci/slots/<slot>/attention interface rather
than using NPEM/_DSM or led_classdev as suggested. The "attention"
interface is more beneficial for our site, since it allows us to
control the NVMe slot LEDs agnostically across different enclosure
vendors and kernel versions using the same scripts.

Basically, /sys/bus/pci/slots/<slot>/attention is already the standard way to control PCI slot LEDs. Our management scripts have used it for years to mark faulted drives for replacement.

I think you can make the case that the PCI hotplug subsystem itself should be updated to export their "attention" values via the LED subsystem. Then all PCI hotplug slots (including Cray E1000) would be exported via the LED subsystem. That work goes beyond the scope of this driver though.

-Tony