Re: [PATCH] hwmon: (pmbus/xdpe1a2g7b) Add regulator support

[Abdurrahman Hussain]

On Sat, 20 Jun 2026 06:53:57 +0000, sashiko-bot@xxxxxxxxxx wrote:
> [Severity: Critical]
> This is a pre-existing issue, but does enabling regulator support here expose
> attached hardware to destructive voltages when operating in nvidia195mv VID
> mode?
>
> The core PMBus framework translates microvolts into raw register encodings via
> pmbus_data2reg_vid(), but it currently hardcodes the VR11 VID calculation
> formula and completely ignores the vrm_version parameter configured by the
> driver.

Good catch! Confirmed: pmbus_data2reg_vid() ignores vrm_version while its
read counterpart pmbus_reg2data_vid() already switches on it, so a non-VR11
driver that exposes a regulator -- or any hwmon vout_command setter -- will
write VR11-encoded values into the chip. For an nvidia195mv part this turns
a 200 mV request into VID 0xB2, which the chip interprets as 1080 mV.

I'll send the core fix as a separate prerequisite patch (mirroring
pmbus_reg2data_vid() so writes round-trip with reads) and respin this
series on top of it.

Thanks,
Abdurrahman