[PATCH] resolved: [ACPI] throttling trouble

[Dominik B. <de...@br...>]

Hi!

Finally I found the bug which disables throttling with any PIIX4 chipset. The 
current code overwrites seemingly unused P_CNT bits with zero. This causes 
some flags in the PIIX4/PIIX4E/PIIX4M chipsets to be un-set, especially the 
CC_EN flag which enables all processor power management. This patch resolves 
these issues. Changes:

x read u32 integers as we write u32 integers
x make duty_mask work again

Oh, and one further comment: Dave Jones' Mhz-detection tool still returns the 
CPU's core frequency, even though throttling does work now.

Dominik

--- linux/drivers/acpi/acpi_processor.c.orig	Tue Mar 12 09:05:14 2002
+++ linux/drivers/acpi/acpi_processor.c	Tue Mar 12 10:37:23 2002
@@ -778,7 +778,7 @@
 	duty_mask = pr->throttling.state_count - 1;
 	duty_mask <<= pr->throttling.duty_offset;
 
-	value = inb(pr->throttling.address);
+	value = inl(pr->throttling.address);
 
 	/*
 	 * Compute the current throttling state when throttling is enabled
@@ -847,7 +847,7 @@
 		duty_value <<= pr->throttling.duty_offset;
 
 		/* Used to clear all duty_value bits */
-		duty_mask = pr->performance.state_count - 1;
+		duty_mask = pr->throttling.state_count - 1;
 		duty_mask <<= acpi_fadt.duty_offset;
 		duty_mask = ~duty_mask;
 	}
@@ -856,7 +856,7 @@
 	 * Disable throttling by writing a 0 to bit 4.  Note that we must
 	 * turn it off before you can change the duty_value.
 	 */
-	value = inb(pr->throttling.address);
+	value = inl(pr->throttling.address);
 	if (value & 0x10) {
 		value &= 0xFFFFFFEF;
 		outl(value, pr->throttling.address);