diff options
| author | Bob Moore <robert.moore@intel.com> | 2013-10-29 09:29:45 +0800 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-10-30 12:24:22 +0100 |
| commit | e07fcfd89f9bbbc5f655b85b70e6f9b0bb626bac (patch) | |
| tree | f51df8ea58847f0fb01a9803530fddc6eb766269 | |
| parent | ab3b24807adabdc32f8a9d5d7d3902e1e744d139 (diff) | |
ACPICA: Hardcode access width for the reset register.
The ACPI spec requires the reset register width to be 8, so we
now hardcode it and ignore the FADT value. This provides/maintains
compatibility with other ACPI implementations that have allowed
BIOS code with bad register width values to go unnoticed.
Matthew Garett, Bob Moore, Lv Zheng.
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| -rw-r--r-- | drivers/acpi/acpica/hwxface.c | 10 | ||||
| -rw-r--r-- | include/acpi/actypes.h | 1 |
2 files changed, 9 insertions, 2 deletions
diff --git a/drivers/acpi/acpica/hwxface.c b/drivers/acpi/acpica/hwxface.c index f81fb068d20e..d3682c2ae0d1 100644 --- a/drivers/acpi/acpica/hwxface.c +++ b/drivers/acpi/acpica/hwxface.c @@ -83,11 +83,17 @@ acpi_status acpi_reset(void) * For I/O space, write directly to the OSL. This bypasses the port * validation mechanism, which may block a valid write to the reset * register. - * Spec section 4.7.3.6 requires register width to be 8. + * + * NOTE: + * The ACPI spec requires the reset register width to be 8, so we + * hardcode it here and ignore the FADT value. This maintains + * compatibility with other ACPI implementations that have allowed + * BIOS code with bad register width values to go unnoticed. */ status = acpi_os_write_port((acpi_io_address) reset_reg->address, - acpi_gbl_FADT.reset_value, 8); + acpi_gbl_FADT.reset_value, + ACPI_RESET_REGISTER_WIDTH); } else { /* Write the reset value to the reset register */ diff --git a/include/acpi/actypes.h b/include/acpi/actypes.h index fed5af2bcb93..63909d9c2f7a 100644 --- a/include/acpi/actypes.h +++ b/include/acpi/actypes.h @@ -349,6 +349,7 @@ typedef u32 acpi_physical_address; #define ACPI_PM1_REGISTER_WIDTH 16 #define ACPI_PM2_REGISTER_WIDTH 8 #define ACPI_PM_TIMER_WIDTH 32 +#define ACPI_RESET_REGISTER_WIDTH 8 /* Names within the namespace are 4 bytes long */ |