1 files changed, 4 insertions, 3 deletions

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index af9f2afd72da..f8d2b2f47fd4 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -287,10 +287,10 @@ static void acpi_processor_idle(void)
                 pr->power.bm_check_timestamp = jiffies;
 
                 /*
-                 * Apply bus mastering demotion policy.  Automatically demote
+                 * If bus mastering is or was active this jiffy, demote
                  * to avoid a faulty transition.  Note that the processor
                  * won't enter a low-power state during this call (to this
-                 * funciton) but should upon the next.
+                 * function) but should upon the next.
                  *
                  * TBD: A better policy might be to fallback to the demotion
                  *      state (use it for this quantum only) istead of
@@ -298,7 +298,8 @@ static void acpi_processor_idle(void)
                  *      qualification.  This may, however, introduce DMA
                  *      issues (e.g. floppy DMA transfer overrun/underrun).
                  */
-                if (pr->power.bm_activity & cx->demotion.threshold.bm) {
+                if ((pr->power.bm_activity & 0x1) &&
+                    cx->demotion.threshold.bm) {
                         local_irq_enable();
                         next_state = cx->demotion.state;
                         goto end;