Commit 199785ea authored by Matthias-Christian Ott's avatar Matthias-Christian Ott Committed by Dave Jones

[CPUFREQ] p4-clockmod reports wrong frequency.

http://bugzilla.kernel.org/show_bug.cgi?id=10968

[ Updated for current tree, and fixed compile failure
  when p4-clockmod was built modular -- davej]

From: Matthias-Christian Ott <ott@mirix.org>
Signed-off-by: default avatarDominik Brodowski <linux@brodo.de>
Signed-off-by: default avatarDave Jones <davej@redhat.com>
parent 0cb8bc25
......@@ -11,8 +11,8 @@ unsigned long native_calibrate_tsc(void);
#ifdef CONFIG_X86_32
extern int timer_ack;
#endif
extern int recalibrate_cpu_khz(void);
#endif /* CONFIG_X86_32 */
extern int no_timer_check;
......
......@@ -31,6 +31,7 @@
#include <asm/processor.h>
#include <asm/msr.h>
#include <asm/timer.h>
#include "speedstep-lib.h"
......@@ -224,6 +225,12 @@ static int cpufreq_p4_cpu_init(struct cpufreq_policy *policy)
dprintk("has errata -- disabling low frequencies\n");
}
if (speedstep_detect_processor() == SPEEDSTEP_CPU_P4D &&
c->x86_model < 2) {
/* switch to maximum frequency and measure result */
cpufreq_p4_setdc(policy->cpu, DC_DISABLE);
recalibrate_cpu_khz();
}
/* get max frequency */
stock_freq = cpufreq_p4_get_frequency(c);
if (!stock_freq)
......
......@@ -16,6 +16,7 @@
#include <linux/slab.h>
#include <asm/msr.h>
#include <asm/tsc.h>
#include "speedstep-lib.h"
#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, \
......@@ -178,6 +179,15 @@ static unsigned int pentium4_get_frequency(void)
u32 msr_lo, msr_hi, mult;
unsigned int fsb = 0;
unsigned int ret;
u8 fsb_code;
/* Pentium 4 Model 0 and 1 do not have the Core Clock Frequency
* to System Bus Frequency Ratio Field in the Processor Frequency
* Configuration Register of the MSR. Therefore the current
* frequency cannot be calculated and has to be measured.
*/
if (c->x86_model < 2)
return cpu_khz;
rdmsr(0x2c, msr_lo, msr_hi);
......@@ -188,10 +198,7 @@ static unsigned int pentium4_get_frequency(void)
* revision #12 in Table B-1: MSRs in the Pentium 4 and
* Intel Xeon Processors, on page B-4 and B-5.
*/
if (c->x86_model < 2)
fsb = 100 * 1000;
else {
u8 fsb_code = (msr_lo >> 16) & 0x7;
fsb_code = (msr_lo >> 16) & 0x7;
switch (fsb_code) {
case 0:
fsb = 100 * 1000;
......@@ -203,7 +210,6 @@ static unsigned int pentium4_get_frequency(void)
fsb = 200 * 1000;
break;
}
}
if (!fsb)
printk(KERN_DEBUG PFX "couldn't detect FSB speed. "
......
......@@ -523,8 +523,6 @@ unsigned long native_calibrate_tsc(void)
return tsc_pit_min;
}
#ifdef CONFIG_X86_32
/* Only called from the Powernow K7 cpu freq driver */
int recalibrate_cpu_khz(void)
{
#ifndef CONFIG_SMP
......@@ -546,7 +544,6 @@ int recalibrate_cpu_khz(void)
EXPORT_SYMBOL(recalibrate_cpu_khz);
#endif /* CONFIG_X86_32 */
/* Accelerators for sched_clock()
* convert from cycles(64bits) => nanoseconds (64bits)
......
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