[PATCH 2/2 v2] smbios: Fallback to the default DT if sysinfo nodes are missing

[Ilias Apalodimas]

Hi Tom,

On Sat, 9 Dec 2023 at 20:49, Tom Rini <trini at konsulko.com> wrote:
>
> On Wed, Dec 06, 2023 at 06:03:14PM +0200, Ilias Apalodimas wrote:
> > Hi Simon,
> >
> > On Sat, 2 Dec 2023 at 20:28, Simon Glass <sjg at chromium.org> wrote:
> > >
> > > Hi Ilias,
> > >
> > > On Wed, 29 Nov 2023 at 23:50, Ilias Apalodimas
> > > <ilias.apalodimas at linaro.org> wrote:
> > > >
> > > > Hi Simon,
> > > >
> > > > [...]
> > > >
> > > >> > Changes since v1:
> > > >> > - Tokenize the DT node entry and use the appropriate value instead of
> > > >> >   the entire string
> > > >> > - Removed Peters tested/reviewed-by tags due to the above
> > > >> >  lib/smbios.c | 94 +++++++++++++++++++++++++++++++++++++++++++++++++---
> > > >> >  1 file changed, 90 insertions(+), 4 deletions(-)
> > > >> >
> > > >>
> > > >> Can this be put behind a Kconfig? It adds quite a bit of code which
> > > >> punishes those boards which do the right thing.
> > > >
> > > >
> > > > Sure but OTOH the code increase should be really minimal. But I don't mind I can add a Kconfig
> > > >
> > > >>
> > > >> > +
> > > >> > +       dt_str = ofnode_read_string(ofnode_root(), nprop->dt_str);
> > > >>
> > > >> Could this use ofnode_read_string_index() ?
> > > >
> > > >
> > > > Maybe, I'll have a look and change it if that works
> >
> > Unless I am missing something this doesn't work.
> > This is designed to return a string index from a DT property that's defined as
> > foo_property = "value1", "value2" isn't it?
> >
> > The code above is trying to read an existing property (e.g compatible)
> > and get the string after the comma delimiter.
> > Perhaps I should add this in drivers/core/ofnode.c instead?
> >
> > > >
> > > > [...]
> > > >
> > > >>
> > > >> Any chance of a test for this code?
> > > >
> > > >
> > > > Sure, but any suggestions on where to add the test?
> > > > SMBIOS tables are populated on OS booting, do we have a test somewhere that boots an OS?
> > >
> > > They are written on startup, right? They should certainly be in place
> > > before U-Boot enters the command line.
> >
> > Not always.  I am not sure if x86 does that, but on the rest of the
> > architectures, they are only initialized when the efi smbios code
> > runs. Wasn't this something you were trying to change?
>
> One of those things I keep repeating is that we don't know for sure what
> the right values here are until we load the DT the OS _will_ use. It's
> quite valid to start U-Boot and pass it a generic "good enough" DT at
> run time until U-Boot can see (GPIOs, EEPROM, whatever) what it's on and
> what the real DT to load before passing to the OS is. Since U-Boot
> doesn't need SMBIOS tables itself, we should make these "late" not
> "early".

Fair enough, we can defer the init and testing of those late, just
before we are about to boot. But this is irrelevant to what this patch
does, can we get the fallback mechanism in first, assuming everyone is
ok with the patch now?

Thanks
/Ilias
>
> --
> Tom