From: Bob Moore <robert.moore@xxxxxxxxx>
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@xxxxxxxxx>
Signed-off-by: Lv Zheng <lv.zheng@xxxxxxxxx>
---
drivers/acpi/acpica/hwxface.c | 10 ++++++++--
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 f81fb06..d3682c2 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 fed5af2..63909d9 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 */
--
1.7.10
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