Re: [PATCH v2 3/4] dt-bindings: rng: Add vmgenid support

From: Jason A. Donenfeld
Date: Tue Mar 26 2024 - 10:44:29 EST


On Tue, Mar 26, 2024 at 01:06:16PM +0000, Landge, Sudan wrote:
> >>> Does the spec say anything about endianness or access size? DT assumes
> >>> native endianness by default. We have properties to deal these, but
> >>> would be better to be explicit if that's defined already.
> >>>
> >> The spec doesn't mention anything about the endianness but, I have
> >> updated the description with some more data.
> >
> > Then what does your driver assume? Microsoft may not have thought
> > about it because they don't care, but now you want to use DT so you
> > have to because it is frequently used on BE systems. If we define
> > something, then there's some hope. Otherwise, it's pretty much a
> > guarantee folks will do the opposite.
> >
> > Rob
> The driver does not assume any endianness. To provide more context, The
> hypervisor stores a 128bit unique ID at the address pointed by the
> "reg"'s 1st cell, driver memcpy's this ID to an internal context and
> uses memcmp to compare if the ID is new or old.
> But yes, it will be good to define a fixed endianness to avoid any
> error. I will update the description to use little endian.

It's a 16-byte blob. Why care about endianness at all here? Treat it as
a byte string, not an integer.

Jason