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
https://bugzilla.kernel.org/show_bug.cgi?id=11533
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 <jrg.otte@googlemail.com>
Cc: linux-acpi@vger.kernel.org
Cc: Len Brown <lenb@kernel.org>
Cc: Peter Anvin <hpa@zytor.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/acpi/reboot.c b/drivers/acpi/reboot.c
index c1d6124..a6c77e8b 100644
--- a/drivers/acpi/reboot.c
+++ b/drivers/acpi/reboot.c
@@ -23,7 +23,8 @@
/* Is the reset register supported? The spec says we should be
* checking the bit width and bit offset, but Windows ignores
* these fields */
- /* Ignore also acpi_gbl_FADT.flags.ACPI_FADT_RESET_REGISTER */
+ if (!(acpi_gbl_FADT.flags & ACPI_FADT_RESET_REGISTER))
+ return;
reset_value = acpi_gbl_FADT.reset_value;