[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: Dominik Brodowski <linux@brodo.de>
Signed-off-by: Dave Jones <davej@redhat.com>

diff --git a/arch/x86/include/asm/timer.h b/arch/x86/include/asm/timer.h
index 2bb6a83..4f5c247 100644 (file)
--- a/arch/x86/include/asm/timer.h
+++ b/arch/x86/include/asm/timer.h
@@ -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;
 

diff --git a/arch/x86/kernel/cpu/cpufreq/p4-clockmod.c b/arch/x86/kernel/cpu/cpufreq/p4-clockmod.c
index 46a2a7a..1778402 100644 (file)
--- a/arch/x86/kernel/cpu/cpufreq/p4-clockmod.c
+++ b/arch/x86/kernel/cpu/cpufreq/p4-clockmod.c
@@ -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)

diff --git a/arch/x86/kernel/cpu/cpufreq/speedstep-lib.c b/arch/x86/kernel/cpu/cpufreq/speedstep-lib.c
index 55c696d..2e3c686 100644 (file)
--- a/arch/x86/kernel/cpu/cpufreq/speedstep-lib.c
+++ b/arch/x86/kernel/cpu/cpufreq/speedstep-lib.c
@@ -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);
 
@@ -188,21 +198,17 @@ 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_code = (msr_lo >> 16) & 0x7;
+       switch (fsb_code) {
+       case 0:
                fsb = 100 * 1000;
-       else {
-               u8 fsb_code = (msr_lo >> 16) & 0x7;
-               switch (fsb_code) {
-               case 0:
-                       fsb = 100 * 1000;
-                       break;
-               case 1:
-                       fsb = 13333 * 10;
-                       break;
-               case 2:
-                       fsb = 200 * 1000;
-                       break;
-               }
+               break;
+       case 1:
+               fsb = 13333 * 10;
+               break;
+       case 2:
+               fsb = 200 * 1000;
+               break;
        }
 
        if (!fsb)

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 599e581..5ad22f8 100644 (file)
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -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)