From: Bob Moore <robert.moore@xxxxxxxxx>
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@xxxxxxxxx>
Signed-off-by: Lin Ming <ming.m.lin@xxxxxxxxx>
Signed-off-by: Len Brown <len.brown@xxxxxxxxx>
---
drivers/acpi/acpica/aclocal.h | 10 +++++++++-
drivers/acpi/acpica/hwregs.c | 15 +++++++++++++++
2 files changed, 24 insertions(+), 1 deletions(-)
diff --git a/drivers/acpi/acpica/aclocal.h b/drivers/acpi/acpica/aclocal.h
index 18a8d96..f01e155 100644
--- a/drivers/acpi/acpica/aclocal.h
+++ b/drivers/acpi/acpica/aclocal.h
@@ -780,7 +780,15 @@ struct acpi_bit_register_info {
* must be preserved.
*/
#define ACPI_PM1_STATUS_PRESERVED_BITS 0x0800 /* Bit 11 */
-#define ACPI_PM1_CONTROL_PRESERVED_BITS 0x0200 /* Bit 9 (whatever) */
+
+/* For control registers, both ignored and reserved bits must be preserved */
+
+#define ACPI_PM1_CONTROL_IGNORED_BITS 0x0201 /* Bits 9, 0(SCI_EN) */
+#define ACPI_PM1_CONTROL_RESERVED_BITS 0xC1F8 /* Bits 14-15, 3-8 */
+#define ACPI_PM1_CONTROL_PRESERVED_BITS \
+ (ACPI_PM1_CONTROL_IGNORED_BITS | ACPI_PM1_CONTROL_RESERVED_BITS)
+
+#define ACPI_PM2_CONTROL_PRESERVED_BITS 0xFFFFFFFE /* All except bit 0 */
/*
* Register IDs
diff --git a/drivers/acpi/acpica/hwregs.c b/drivers/acpi/acpica/hwregs.c
index fd7abe2..6117362 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;
--
1.6.0.6
--
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