On Thu, Sep 05, 2024 at 08:19:25AM +0200, Mariusz Tkaczyk wrote: > On Tue, 3 Sep 2024 17:18:20 -0500 > Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote: > > > On Tue, Aug 27, 2024 at 02:03:48PM -0700, Tony Hutter wrote: > > > Add driver to control the NVMe slot LEDs on the Cray ClusterStor E1000. > > > The driver provides hotplug attention status callbacks for the 24 NVMe > > > slots on the E1000. This allows users to access the E1000's locate and > > > fault LEDs via the normal /sys/bus/pci/slots/<slot>/attention sysfs > > > entries. This driver uses IPMI to communicate with the E1000 controller to > > > toggle the LEDs. > > > > I hope/assume the interface is the same as one of the others, i.e., > > the existing one added for NVMe behind VMD by > > https://git.kernel.org/linus/576243b3f9ea ("PCI: pciehp: Allow > > exclusive userspace control of indicators") or the new one for NPEM > > and the _DSM at > > https://lore.kernel.org/linux-pci/20240814122900.13525-3-mariusz.tkaczyk@xxxxxxxxxxxxxxx/ > > > > I suppose we intend that the ledmon utility will be able to drive > > these LEDs? Whatever the user, we should try to minimize the number > > of different interfaces for this functionality. > > Ledmon won't support it, at least not in current form. Ledmon > support for pciehp attention is limited to VMD, i.e. first we must > find VMD driver then we are looking for slot/attention. I'm not > familiar with any attempt to add support for this in ledmon. > > From the end user perspective, I don't like pciehp/attention because > we are refereeing to pciehp driver not pcieport and to determine > proper slot we need to do additional matching by slot/address. I > would be simpler. > https://github.com/intel/ledmon/blob/main/src/lib/vmdssd.c#L100 All I'm trying to say is that NPEM, the related _DSM, and the VMD special case are all ways to control NVMe slot IDs. This Cray thing is another. We already have two user interfaces (the NPEM/_DSM one and the VMD one), and I'd like to avoid adding a third.
