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ACPICA: Hardcode access width for the reset register.

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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>
This commit is contained in:
Bob Moore 2013-10-29 09:29:45 +08:00 committed by Rafael J. Wysocki
parent ab3b24807a
commit e07fcfd89f
2 changed files with 9 additions and 2 deletions
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10
drivers/acpi/acpica/hwxface.c
View File

@ -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 */

1
include/acpi/actypes.h
View File

@ -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 */