Re: [PATCH] hwmon: Add driver for MSI Mystic Light controller voltage sensors

[Guenter Roeck]

On 11/7/26 00:27, Tomasz Bojanowski wrote:
> Your reply did not reach my inbox, because the spam filtering at my mail
> provider was set too strictly. I have fixed that, and I read your review
> on lore.

There is nothing I can do about that, sorry. No matter which provider I use
to send e-mail, some provider somewhere considers it to be spam.

> Thanks for the review, and for trying the driver on your boards.
>
> On 11/6/26 16:36, Guenter Roeck wrote:
> > Using the USB serial number to detect the device seems fragile. If the
> > USB vendor/product ID can not be used for some reason, it might make
> > more sense to implement a DMI match.
>
> Agreed. v2 identifies the board by DMI only and no longer looks at the
> serial number. The driver is only registered on supported boards.
>
> > This will require additional per-board data. On MAG B650M
> > MORTAR WIFI (MS-7D76), the USB IDs are 1462:7d76, and
> > hid_hw_raw_request() with the parameters below returns
> > a length of 0 bytes. On MAG B650 TOMAHAWK WIFI (MS-7D75),
> > the USB device ID is 1462:7d75, and on MAG B550M MORTAR
> > (MS-7C94) it is 1462:7c94.
> >
> > That makes me wonder if the parameters can be associated
> > with USB IDs.
>
> On these older boards the controller uses the board code as its
> product ID (1462:7dxx, 1462:7cxx). As far as I can tell from the vendor
> software, the sensors of these controllers are read with a different
> request, not with feature report 0xf0, which would be consistent with
> the 0 byte reply. I have not verified this on hardware.

I have the ones mentioned above, so I could test there if you want to
add support for it.

> On the 800-series boards the controller uses a common ID, 0db0:0076.
> OpenRGB lists more than 30 X870, B850, B840 and Z890 boards behind this
> ID and selects its per-board LED configuration by the DMI board name.
> The vendor software also handles these boards with one class and tells
> them apart by the USB serial number. So the USB ID does not identify
> the board there, which is why v2 uses DMI.
>
> For now the driver only covers the 800-series controller on the MAG
> B850M MORTAR WIFI (MS-7E61), which is the board I can test on.
>
> v2 also addresses the issues reported by Sashiko and your other
> comments: it reads and validates the report in probe, fails probe if
> that does not work, only exposes the rails that return a reading, and
> no longer returns -ENODATA. I will send it as a new thread.

Thanks a lot for the information.

Guenter