1 files changed, 24 insertions, 11 deletions

diff --git a/drivers/acpi/tables/tbfadt.c b/drivers/acpi/tables/tbfadt.c
index ccb5b64bbef3..2c7885e7ffba 100644
--- a/drivers/acpi/tables/tbfadt.c
+++ b/drivers/acpi/tables/tbfadt.c
@@ -50,7 +50,7 @@ ACPI_MODULE_NAME("tbfadt")
 /* Local prototypes */
 static void inline
 acpi_tb_init_generic_address(struct acpi_generic_address *generic_address,
-                             u8 bit_width, u64 address);
+                             u8 byte_width, u64 address);
 
 static void acpi_tb_convert_fadt(void);
 
@@ -111,7 +111,7 @@ static struct acpi_fadt_info fadt_info_table[] = {
  * FUNCTION:    acpi_tb_init_generic_address
  *
  * PARAMETERS:  generic_address     - GAS struct to be initialized
- *              bit_width           - Width of this register
+ *              byte_width          - Width of this register
  *              Address             - Address of the register
  *
  * RETURN:      None
@@ -342,12 +342,21 @@ static void acpi_tb_convert_fadt(void)
          * useful to calculate them once, here.
          *
          * The PM event blocks are split into two register blocks, first is the
-         * PM Status Register block, followed immediately by the PM Enable Register
-         * block. Each is of length (xpm1x_event_block.bit_width/2)
+         * PM Status Register block, followed immediately by the PM Enable
+         * Register block. Each is of length (xpm1x_event_block.bit_width/2).
+         *
+         * On various systems the v2 fields (and particularly the bit widths)
+         * cannot be relied upon, though. Hence resort to using the v1 length
+         * here (and warn about the inconsistency).
          */
-        WARN_ON(ACPI_MOD_16(acpi_gbl_FADT.xpm1a_event_block.bit_width));
-        pm1_register_length = (u8) ACPI_DIV_16(acpi_gbl_FADT
-                                               .xpm1a_event_block.bit_width);
+        if (acpi_gbl_FADT.xpm1a_event_block.bit_width
+            != acpi_gbl_FADT.pm1_event_length * 8)
+                printk(KERN_WARNING "FADT: "
+                       "X_PM1a_EVT_BLK.bit_width (%u) does not match"
+                       " PM1_EVT_LEN (%u)\n",
+                       acpi_gbl_FADT.xpm1a_event_block.bit_width,
+                       acpi_gbl_FADT.pm1_event_length);
+        pm1_register_length = (u8) ACPI_DIV_2(acpi_gbl_FADT.pm1_event_length);
 
         /* The PM1A register block is required */
 
@@ -362,10 +371,13 @@ static void acpi_tb_convert_fadt(void)
         /* The PM1B register block is optional, ignore if not present */
 
         if (acpi_gbl_FADT.xpm1b_event_block.address) {
-                WARN_ON(ACPI_MOD_16(acpi_gbl_FADT.xpm1b_event_block.bit_width));
-                pm1_register_length = (u8) ACPI_DIV_16(acpi_gbl_FADT
-                                                       .xpm1b_event_block
-                                                       .bit_width);
+                if (acpi_gbl_FADT.xpm1b_event_block.bit_width
+                    != acpi_gbl_FADT.pm1_event_length * 8)
+                        printk(KERN_WARNING "FADT: "
+                               "X_PM1b_EVT_BLK.bit_width (%u) does not match"
+                               " PM1_EVT_LEN (%u)\n",
+                               acpi_gbl_FADT.xpm1b_event_block.bit_width,
+                               acpi_gbl_FADT.pm1_event_length);
                 acpi_tb_init_generic_address(&acpi_gbl_xpm1b_enable,
                                              pm1_register_length,
                                              (acpi_gbl_FADT.xpm1b_event_block.
@@ -373,6 +385,7 @@ static void acpi_tb_convert_fadt(void)
                 /* Don't forget to copy space_id of the GAS */
                 acpi_gbl_xpm1b_enable.space_id =
                     acpi_gbl_FADT.xpm1b_event_block.space_id;
+
         }
 }