Re: [PATCH 0/4] Fix regressions uncovered by bad_madt_entry() patches

["Rafael J. Wysocki" <rjw@rjwysocki.net>]

On Wednesday, October 14, 2015 03:26:21 PM Al Stone wrote:
> Once the patch series "Provide better MADT subtable sanity checks" got
> into linux-next (commit b9e11e92b9), several existing platforms were found
> where the firmware was doing odd things that aren't exactly correct if
> the ACPI specification is being followed precisely.  This patch series
> relaxes some of the checks on MADT subtables so that these previously 
> working systems (all x86-based) will continue to boot.  For arm64, since
> ACPI usage is still relatively new, the stricter checking is left in place.
> 
> Al Stone (4):
>   ACPI: workaround x86 firmware using reserved MADT subtable IDs
>   ACPI: workaround x86 firmware with mis-matched FADT/MADT revisions
>   ACPI: workaround FADT always being revision 2
>   ACPI: for bad_madt_entry(), the GIC ITS table is 20 bytes long, not 16
> 
>  drivers/acpi/tables.c | 62 ++++++++++++++++++++++++++++++++++++++++++---------
>  1 file changed, 51 insertions(+), 11 deletions(-)

Honestly, having reviewed this series I'm inclined to drop the original
changes from my tree and ask you to start over.

It seems to have been a mistake to modify the existing behavior for x86 and
goodness only knows about ia64.  The changes for these architectures don't make
us better off in any way.

I understand the motivation to keep ARM64 "fresh and clean", but there must be
a way to do that without affecting the other architectures negatively.

Thanks,
Rafael