Revert "ACPI: ignore FADT reset-reg-sup flag"

This reverts commit cf450136bfde77c7f95065c91bffded4aa7fa731.

It breaks reboot on at least one Thinkpad T43, as reported by Jörg Otte:
 "On reboot it shuts down as normal.
  The last lines displayed are:

  >Unmounting temporary filesystems.. [OK]
  >Deactivating swap...               [OK]
  >Unmounting local filesystems...    [OK]
  >Will now restart
  >    Restarting system

  Then I hear it accessing the cd-drive, but then it's being stuck."

Jörg bisected the regression to this commit.

That commit fixes another machine (see

for details) that has a BIOS bug and doesn't support ACPI reset.
However, at least one of those other reporters no longer even has the
machine in question, and had a different workaround to begin with.
Besides, it clearly was a buggy BIOS.  Let's not break the correct case
to fix that case.

Reported-and-bisected-by: Jörg Otte <>
Cc: Len Brown <>
Cc: Peter Anvin <>
Signed-off-by: Linus Torvalds <>
2 files changed