From 19244ad06b70ed84931df868583547ce1cd3a186 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Fri, 20 Apr 2012 11:19:35 -0700 Subject: [PATCH] Revert "ACPI: ignore FADT reset-reg-sup flag" MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Cc: linux-acpi@vger.kernel.org Cc: Len Brown Cc: Peter Anvin Signed-off-by: Linus Torvalds --- drivers/acpi/acpica/hwxface.c | 3 ++- drivers/acpi/reboot.c | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/acpi/acpica/hwxface.c b/drivers/acpi/acpica/hwxface.c index ab513a972c95..a716fede4f25 100644 --- a/drivers/acpi/acpica/hwxface.c +++ b/drivers/acpi/acpica/hwxface.c @@ -74,7 +74,8 @@ acpi_status acpi_reset(void) /* Check if the reset register is supported */ - if (!reset_reg->address) { + if (!(acpi_gbl_FADT.flags & ACPI_FADT_RESET_REGISTER) || + !reset_reg->address) { return_ACPI_STATUS(AE_NOT_EXIST); } diff --git a/drivers/acpi/reboot.c b/drivers/acpi/reboot.c index c1d612435939..a6c77e8b37bd 100644 --- a/drivers/acpi/reboot.c +++ b/drivers/acpi/reboot.c @@ -23,7 +23,8 @@ void acpi_reboot(void) /* 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;