diff options
| author | Bob Moore <robert.moore@intel.com> | 2009-03-13 09:10:46 +0800 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2009-03-27 12:11:03 -0400 |
| commit | 20869dcfde204e1c21b642608d708d82472fee2b (patch) | |
| tree | a3e6dca8ff835def8ba6a41606aa30cac5d9fa1c /drivers/acpi/acpica/hwregs.c | |
| parent | 8636f8d257b3edf5a1529df93119cdc630ed85c7 (diff) | |
ACPICA: Preserve all PM control reserved and ignored bits
As per the ACPI specification, preserve (read/modify/write) all
bits that are defined as either reserved or ignored (PM control
control registers only.)
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>
Diffstat (limited to 'drivers/acpi/acpica/hwregs.c')
| -rw-r--r-- | drivers/acpi/acpica/hwregs.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/drivers/acpi/acpica/hwregs.c b/drivers/acpi/acpica/hwregs.c index fd7abe277db3..611736266f9f 100644 --- a/drivers/acpi/acpica/hwregs.c +++ b/drivers/acpi/acpica/hwregs.c @@ -328,6 +328,21 @@ acpi_status acpi_hw_register_write(u32 register_id, u32 value) case ACPI_REGISTER_PM2_CONTROL: /* 8-bit access */ + /* + * For control registers, all reserved bits must be preserved, + * as per the ACPI spec. + */ + status = + acpi_read(&read_value, &acpi_gbl_FADT.xpm2_control_block); + if (ACPI_FAILURE(status)) { + goto exit; + } + + /* Insert the bits to be preserved */ + + ACPI_INSERT_BITS(value, ACPI_PM2_CONTROL_PRESERVED_BITS, + read_value); + status = acpi_write(value, &acpi_gbl_FADT.xpm2_control_block); break; |