ACPI: C-States: bm_activity improvements
Do not assume there was bus mastering activity if the idle handler didn't get
called, as there's only reason to not enter C3-type sleep if there is bus
master activity going on. Only for the "promotion" into C3-type sleep bus
mastering activity is taken into account, and there only current bus mastering
activity, and not pure guessing should lead to the decision on whether to
enter C3-type sleep or not.
Also, as bm_activity is a jiffy-based bitmask (bit 0: bus mastering activity
during this juffy, bit 31: bus mastering activity 31 jiffies ago), fix the
setting of bit 0, as it might be called multiple times within one jiffy.
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 6d1e238..af9f2af 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -3,7 +3,7 @@
*
* Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
* Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
- * Copyright (C) 2004 Dominik Brodowski <linux@brodo.de>
+ * Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de>
* Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
* - Added processor hotplug support
* Copyright (C) 2005 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
@@ -261,21 +261,15 @@
u32 bm_status = 0;
unsigned long diff = jiffies - pr->power.bm_check_timestamp;
- if (diff > 32)
- diff = 32;
+ if (diff > 31)
+ diff = 31;
- while (diff) {
- /* if we didn't get called, assume there was busmaster activity */
- diff--;
- if (diff)
- pr->power.bm_activity |= 0x1;
- pr->power.bm_activity <<= 1;
- }
+ pr->power.bm_activity <<= diff;
acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS,
&bm_status, ACPI_MTX_DO_NOT_LOCK);
if (bm_status) {
- pr->power.bm_activity++;
+ pr->power.bm_activity |= 0x1;
acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS,
1, ACPI_MTX_DO_NOT_LOCK);
}
@@ -287,7 +281,7 @@
else if (errata.piix4.bmisx) {
if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
|| (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
- pr->power.bm_activity++;
+ pr->power.bm_activity |= 0x1;
}
pr->power.bm_check_timestamp = jiffies;
