Re: [PATCH v2 1/2] ACPI: FPDT: expose FBPT and S3PT subtables via sysfs

[Nate DeSimone <nathaniel.l.desimone@intel.com>]

On Wed, 11 Mar 2026 14:18:13 +0100 Rafael J. Wysocki
<rafael@kernel.org> wrote:
> On Tue, Mar 10, 2026 at 5:35=E2=80=AFAM Nate DeSimone
> <nathaniel.l.desimone@intel.com> wrote:
> >
> > +static BIN_ATTR(FBPT, 0400, sysfs_bin_attr_simple_read, NULL, 0);
> > +static BIN_ATTR(S3PT, 0400, sysfs_bin_attr_simple_read, NULL, 0);
> > +
> >  static struct kobject *fpdt_kobj;
> >
> >  #if defined CONFIG_X86 && defined CONFIG_PHYS_ADDR_T_64BIT
> > @@ -254,9 +257,34 @@ static int fpdt_process_subtable(u64 address, u32 su=
> btable_type)
> >                         break;
> >                 }
> >         }
> > +
> > +       if (subtable_type =3D=3D SUBTABLE_FBPT) {
> > +               bin_attr_FBPT.private =3D subtable_header;
> > +               bin_attr_FBPT.size =3D length;
> > +               result =3D sysfs_create_bin_file(fpdt_kobj, &bin_attr_FBP=
> T);
> > +               if (result)
> > +                       goto err;
>
> Is failing the function the right thing to do here (and below).
>
> A failure to create the sysfs attribute is not critical I suppose, so
> would printing a message be sufficient?

Thank you for the feedback!

I have sent a new V3 patch series with the sysfs_create_bin_file() failure
handling changed from a hard error to a non-fatal warning.

> > +       } else if (subtable_type =3D=3D SUBTABLE_S3PT) {
> > +               bin_attr_S3PT.private =3D subtable_header;
> > +               bin_attr_S3PT.size =3D length;
> > +               result =3D sysfs_create_bin_file(fpdt_kobj, &bin_attr_S3P=
> T);
> > +               if (result)
> > +                       goto err;
> > +       }
> > +
> >         return 0;
> >
> >  err:
> > +       if (bin_attr_FBPT.private) {
> > +               sysfs_remove_bin_file(fpdt_kobj, &bin_attr_FBPT);
> > +               bin_attr_FBPT.private =3D NULL;
> > +       }
> > +
> > +       if (bin_attr_S3PT.private) {
> > +               sysfs_remove_bin_file(fpdt_kobj, &bin_attr_S3PT);
> > +               bin_attr_S3PT.private =3D NULL;
> > +       }
> > +
> >         if (record_boot)
> >                 sysfs_remove_group(fpdt_kobj, &boot_attr_group);
> >
> >
> > base-commit: 8bf22c33e7a172fbc72464f4cc484d23a6b412ba
> > --

Best Regards,
-Nate