From: Dominik Brodowski Date: Sat, 24 Jun 2006 23:37:00 +0000 (-0400) Subject: ACPI: C-States: bm_activity improvements X-Git-Tag: v2.6.18-rc1~257^2~5^2~1 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c5ab81ca01ad4a8870b456f93dd2fb3d815f91d9;p=linux-2.6 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 Signed-off-by: Andrew Morton Signed-off-by: Len Brown --- diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 6d1e238e23..af9f2afd72 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -3,7 +3,7 @@ * * Copyright (C) 2001, 2002 Andy Grover * Copyright (C) 2001, 2002 Paul Diefenbaugh - * Copyright (C) 2004 Dominik Brodowski + * Copyright (C) 2004, 2005 Dominik Brodowski * Copyright (C) 2004 Anil S Keshavamurthy * - Added processor hotplug support * Copyright (C) 2005 Venkatesh Pallipadi @@ -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;