Re: [PATCH 10/12] ACPI: processor: refactor internal map_lsapic_id()

Alex Chiang
2010-01-25T23:01:53Z

Hi David,

* David Rientjes <rientjes@google.com>:
> On Mon, 25 Jan 2010, Alex Chiang wrote:
>
> > diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
> > index 9213f95..ec5989c 100644
> > --- a/drivers/acpi/processor_core.c
> > +++ b/drivers/acpi/processor_core.c
> > @@ -83,27 +83,17 @@ static int map_lsapic_id(struct acpi_subtable_header *entry,
> > {
> > struct acpi_madt_local_sapic *lsapic =
> > (struct acpi_madt_local_sapic *)entry;
> > - u32 tmp = (lsapic->id << 8) | lsapic->eid;
> >
> > - /* Only check enabled APICs*/
> > if (!(lsapic->lapic_flags & ACPI_MADT_ENABLED))
> > return 0;
> >
> > - /* Device statement declaration type */
> > if (device_declaration) {
> > - if (entry->length < 16)
> > - printk(KERN_ERR PREFIX
> > - "Invalid LSAPIC with Device type processor (SAPIC ID %#x)\n",
> > - tmp);
>
> Why drop this error message?

It didn't seem to add any value.

If BIOS declares a processor with the Device statement in ACPI
and it has an invalid length, there's nothing that a user can do
about it.

Arguably, the message might be useful during internal platform
bringup (or new firmware validation), but even that's a hard sell
to me, since one of the first things a bringup engineer would
notice would be missing CPUs, and it wouldn't take that long to
realize that firmware was broken; why make upstream carry around
extra baggage for internal firmware debugging?

But I don't have a strong opinion here. If folks think that
message is useful, I can respin leaving it in.

Thanks,
/ac