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Commit c5ab81ca authored by Dominik Brodowski's avatar Dominik Brodowski Committed by Len Brown
Browse files

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: default avatarDominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent a3c6598f

drivers/acpi/processor_idle.c

+6 −12
Original line number Diff line number Diff line
@@ -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 @@ static void acpi_processor_idle(void) 
		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 @@ static void acpi_processor_idle(void) 
		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;