[systemd-devel] acpi_index value reported as 0 - not allowed?

[Joe Hershberger]

14 07:39:03 UTC 2018, Andrei Borzenkov wrote:
> 13.09.2018 22:05, Joe Hershberger пишет:
> > Hi,
> >
> > I have a system which reports acpi_index as 0, which matches the
> > labeling on the device. Looking at the source in udev, it seems to be
> > expecting an index greater than 0.
> >
>
> You should have at least mentioned what system it is.

Apologies, I should have elaborated. The system is one that we are in
the middle of developing. It is an x64 target. We are using the DSDT
table to return the function 7 in _DSM.

>
> > Looking at https://www.dmtf.org/sites/default/files/standards/documents/DSP0134_2.7.1.pdf
>
> This is SMBIOS specification while acpi_index is obtained by ACPI _DSM
> method. Unfortunately PCI specifications that define it are not publicly
> accessible.

Is there a statement in the PCI specs that rule out using 0 or are you
simply stating that you can't reference it here?

Thanks,
-Joe

>
> > it provides an example that uses 1 and 2, but I don't see anything
> > that claims that 0 is allowed or disallowed.
> >
> > Would it be reasonable to send a patch that makes udev allow an index
> > of 0 or is there a reason not to allow 0?
> >
> > Thanks,
> > -Joe