ACPI: fix "Time Problems with 2.6.23-rc1-gf695baf2"

Enable C3 without bm control only for CST based C3.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 10 insertions, 4 deletions

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index a898991f77cb..a8634a0655fc 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -969,11 +969,17 @@ static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
         }
 
         if (pr->flags.bm_check) {
-                /* bus mastering control is necessary */
                 if (!pr->flags.bm_control) {
-                        /* In this case we enter C3 without bus mastering */
-                        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-                                "C3 support without bus mastering control\n"));
+                        if (pr->flags.has_cst != 1) {
+                                /* bus mastering control is necessary */
+                                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+                                        "C3 support requires BM control\n"));
+                                return;
+                        } else {
+                                /* Here we enter C3 without bus mastering */
+                                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+                                        "C3 support without BM control\n"));
+                        }
                 }
         } else {
                 /*