Messages in this thread Patch in this message | | | Date | Sat, 31 Dec 2005 12:11:10 +0100 | From | Dominik Brodowski <> | Subject | [PATCH 1/4] ACPI C-States: bm_activity improvements |
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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>
Index: working-tree/drivers/acpi/processor_idle.c =================================================================== --- working-tree.orig/drivers/acpi/processor_idle.c +++ working-tree/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> @@ -224,21 +224,15 @@ 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); } @@ -250,7 +244,7 @@ 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; - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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