Commit f81154a9 authored by Dominik Brodowski's avatar Dominik Brodowski Committed by Christoph Hellwig

[PATCH] cpufreq: correct initialization on Intel Coppermines

cpufreq: Intel Coppermines -- the saga continues.

The detection process for speedstep-enabled Pentium III Coppermines is
considered proprietary by Intel.  The attempt to detect this capability
using MSRs failed.

So, users need to pass the option "speedstep_coppermine=1" to the kernel
(boot option or parameter) if they own a SpeedStep capable PIII
Coppermine processor.  Tualatins work as before.
parent 8371ca70
/*
* $Id: speedstep.c,v 1.53 2002/09/29 23:43:11 db Exp $
* $Id: speedstep.c,v 1.57 2002/11/05 12:01:12 db Exp $
*
* (C) 2001 Dave Jones, Arjan van de ven.
* (C) 2002 Dominik Brodowski <linux@brodo.de>
......@@ -46,7 +46,8 @@ static struct pci_dev *speedstep_chipset_dev;
/* speedstep_processor
*/
static unsigned int speedstep_processor;
static unsigned int speedstep_processor = 0;
static int speedstep_coppermine = 0;
#define SPEEDSTEP_PROCESSOR_PIII_C 0x00000001 /* Coppermine core */
#define SPEEDSTEP_PROCESSOR_PIII_T 0x00000002 /* Tualatin core */
......@@ -72,7 +73,7 @@ static unsigned int speedstep_high_freq;
#ifdef SPEEDSTEP_DEBUG
#define dprintk(msg...) printk(msg)
#else
#define dprintk(msg...) do { } while(0);
#define dprintk(msg...) do { } while(0)
#endif
......@@ -429,7 +430,7 @@ static unsigned int pentium4_get_frequency(void)
/**
* speedstep_detect_processor - detect Intel SpeedStep-capable processors.
*
* Returns the SPEEDSTEP_PROCESSOR_-number for the detected chipset,
* Returns the SPEEDSTEP_PROCESSOR_-number for the detected processor,
* or zero on failure.
*/
static unsigned int speedstep_detect_processor (void)
......@@ -474,8 +475,6 @@ static unsigned int speedstep_detect_processor (void)
return SPEEDSTEP_PROCESSOR_PIII_T;
case 0x08: /* Intel PIII [Coppermine] */
/* based on reverse-engineering information and
* some guessing. HANDLE WITH CARE! */
{
u32 msr_lo, msr_hi;
......@@ -487,21 +486,13 @@ static unsigned int speedstep_detect_processor (void)
if (msr_lo != 0x0080000)
return 0;
/* platform ID seems to be 0x00140000 */
rdmsr(MSR_IA32_PLATFORM_ID, msr_lo, msr_hi);
dprintk(KERN_DEBUG "cpufreq: Coppermine: MSR_IA32_PLATFORM ID is 0x%x, 0x%x\n", msr_lo, msr_hi);
msr_hi = msr_lo & 0x001c0000;
if (msr_hi != 0x00140000)
return 0;
if (speedstep_coppermine)
return SPEEDSTEP_PROCESSOR_PIII_C;
/* and these bits seem to be either 00_b, 01_b or
* 10_b but never 11_b */
msr_lo &= 0x00030000;
if (msr_lo == 0x0030000)
printk(KERN_INFO "cpufreq: in case this is a SpeedStep-capable Intel Pentium III Coppermine\n");
printk(KERN_INFO "cpufreq: processor, please pass the boot option or module parameter\n");
printk(KERN_INFO "cpufreq: `speedstep_coppermine=1` to the kernel. Thanks!\n");
return 0;
/* let's hope this is correct... */
return SPEEDSTEP_PROCESSOR_PIII_C;
}
default:
......@@ -622,6 +613,25 @@ static void speedstep_verify (struct cpufreq_policy *policy)
}
#ifndef MODULE
/**
* speedstep_setup speedstep command line parameter parsing
*
* speedstep command line parameter. Use:
* speedstep_coppermine=1
* if the CPU in your notebook is a SpeedStep-capable Intel
* Pentium III Coppermine. These processors cannot be detected
* automatically, as Intel continues to consider the detection
* alogrithm as proprietary material.
*/
static int __init speedstep_setup(char *str)
{
speedstep_coppermine = simple_strtoul(str, &str, 0);
return 1;
}
__setup("speedstep_coppermine=", speedstep_setup);
#endif
/**
* speedstep_init - initializes the SpeedStep CPUFreq driver
*
......@@ -644,11 +654,12 @@ static int __init speedstep_init(void)
speedstep_processor = speedstep_detect_processor();
if ((!speedstep_chipset) || (!speedstep_processor)) {
dprintk(KERN_INFO "cpufreq: Intel(R) SpeedStep(TM) for this %s not (yet) available.\n", speedstep_processor ? "chipset" : "processor");
printk(KERN_INFO "a 0x%x b 0x%x\n", speedstep_processor, speedstep_chipset);
printk(KERN_INFO "cpufreq: Intel(R) SpeedStep(TM) for this %s not (yet) available.\n", speedstep_chipset ? "processor" : "chipset");
return -ENODEV;
}
dprintk(KERN_INFO "cpufreq: Intel(R) SpeedStep(TM) support $Revision: 1.53 $\n");
dprintk(KERN_INFO "cpufreq: Intel(R) SpeedStep(TM) support $Revision: 1.57 $\n");
dprintk(KERN_DEBUG "cpufreq: chipset 0x%x - processor 0x%x\n",
speedstep_chipset, speedstep_processor);
......@@ -726,3 +737,5 @@ MODULE_DESCRIPTION ("Speedstep driver for Intel mobile processors.");
MODULE_LICENSE ("GPL");
module_init(speedstep_init);
module_exit(speedstep_exit);
MODULE_PARM (speedstep_coppermine, "i");
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