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

[Joe Hershberger]

On Fri, Sep 14, 2018 at 10:30 AM Andrei Borzenkov <arvidjaar at gmail.com> wrote:
>
> 14.09.2018 17:08, Joe Hershberger пишет:
> > 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?
> >
>
> I do not have access to official final specs. The change request is
> available and does not restrict value range. Actually the only
> requirement is that instance numbers be unique.

That's my understanding too. Given that, should I send a patch that
makes udev allow index of 0?

Thanks,
-Joe

>
> https://pcisig.com/sites/default/files/specification_documents/ECR_Slot_Naming-10.pdf
>
> > 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
>
> _______________________________________________
> systemd-devel mailing list
> systemd-devel at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/systemd-devel