Re: VR control from the BMC

[Vijay Khemka <vijaykhemka@fb.com>]

On 10/26/20, 4:04 PM, "openbmc on behalf of Ed Tanous" <openbmc-bounces+vijaykhemka=fb.com@lists.ozlabs.org on behalf of edtanous@google.com> wrote:

    In the near future, I'm going to have some needs for OpenBMC to be
    able to control VRs.  These VRs might be on the baseboard itself, or
    on detected PCIe add-in-cards, and controlled over PMBus.
    Additionally, I will need a "hardware safe" way for the host to be
    able to modify the behavior of these VRs (usually different voltage
    settings), and to have that interface be constrained in such a way
    that the host can never set a value that's outside of a predefined
    range that's known to be safe for the hardware, which the BMC will own
    the definition of for security purposes.

    Does anyone else have similar needs?  I've been pointed to
    phosphor-regulators which has some similar parallels;  As-is, that
    solution won't work for me, because it's relying on fixed, platform
    specific json scripting to accomplish its goals.  My hope would be for
    a more generalized linux devicetree based solution,
 
Voltage limits can certainly be passed via DTS file to limit user
application configuration setting.

    as well as a
    representation on dbus that could be modified at runtime by
    Redfish/IPMI in band.

    Is there any other work I should look into that's similar?  Does
    anyone have any strong opinions on how this should be organized or how
    it could be built?

I would also like to add VR firmware upgrades as well in this.

    Thanks,

    -Ed