On Wed, Feb 24, 2021 at 04:30:42PM +0100, Enrico Weigelt, metux IT consult wrote:

On 24.02.21 09:00, Greg KH wrote:

quoted

Have the firmware code do it itself, do nto try to "reach across" like
this.

By "firmware code" you mean Linux acpi core or the board's bios ?

either.

a) Fixing BIOS would be the cleanest solution, but we cant expect all
   users to do field upgrades. Many of the devices (eg. the customer,
   I've originally wrote the apu board driver for, deployed them in
   really remote locations, sometimes even just reachable by ship,
   heli or horse, litterally)

b) Explicit blacklisting somewhere in apci enumeration code could work,
   but I really hate the idea of such board and bios version specific
   quirks in a place, completely unrelated to the actual board driver.

We have quirks all over the place, that's normal and how we handle
broken hardware/bios al the time.

Actually, I'm also hoping to find a proper way for having those things
in one file per board, in the future. (probably not applicable for
early stuff, or _OSI(Linux), etc)

I don't know what "things" you are referring to here at all.

quoted

And what problem are you really trying to solve here by doing this?

The problem is that *some* bios versions (that came much later, after
pcengines-apuv2 driver went into production) added a few things that
the driver is already doing - different versions doing it differently
(eg. even enumerating gpio connected leds with completely different
names, etc), and still some gpio connected devices missing. Some
versions (just forgot, which one it's been exactly) even enumerate
*some* gpios (and LEDs behind them) as a different device, whose Linux
driver just happens to work. Meanwhile I can't find any reference of
that in the coreboot source, anymore.

I have no idea what you are talking about here, you did not describe a
problem :(

As you can see: bios is anything but reliable on that platform.

I do not understand.

What I'm trying to achieve: the kernel should behave exactly the
same, no matter what board revision, bios version, kernel version,
etc. (there should be especially no need to have special per-board
quirks in userland, depending on board rev, bios version, kernel
version).

If you've got a better solution, I'll be glad to hear it.

I really do not understand the problem, sorry.

greg k-h