ACPICA: acpi_reset: Bypass port validation mechanism

Allow writes to reserved ports. This change may eventually be
driven down in to acpi_write and acpi_read.

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 15 insertions, 2 deletions

diff --git a/drivers/acpi/acpica/hwxface.c b/drivers/acpi/acpica/hwxface.c
index 4ead85f29215..647c7b6e6756 100644
--- a/drivers/acpi/acpica/hwxface.c
+++ b/drivers/acpi/acpica/hwxface.c
@@ -78,9 +78,22 @@ acpi_status acpi_reset(void)
                 return_ACPI_STATUS(AE_NOT_EXIST);
         }
 
-        /* Write the reset value to the reset register */
+        if (reset_reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
+                /*
+                 * 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.
+                 */
+                status =
+                    acpi_os_write_port((acpi_io_address) reset_reg->address,
+                                       acpi_gbl_FADT.reset_value,
+                                       reset_reg->bit_width);
+        } else {
+                /* Write the reset value to the reset register */
+
+                status = acpi_hw_write(acpi_gbl_FADT.reset_value, reset_reg);
+        }
 
-        status = acpi_hw_write(acpi_gbl_FADT.reset_value, reset_reg);
         return_ACPI_STATUS(status);
 }