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authorRafał Bilski <rafalbilski@interia.pl>2007-01-01 23:49:34 +0100
committerDave Jones <davej@redhat.com>2007-01-02 23:38:39 -0500
commit24ebead82bbf9785909d4cf205e2df5e9ff7da32 (patch)
tree921f686860e918a01c3d3fb6cd106ba82bf4ace6
parent264166e604a7e14c278e31cadd1afb06a7d51a11 (diff)
[CPUFREQ] Longhaul - Always guess FSB
This is patch that solves Ebox mini PC issue and make FSB code more specification compilant. At start guess_fsb function is guessing 200MHz FSB too. It is better to make it in this way because, thanks to this function, driver will fail for bogus FSB values caused by bogus multiplier value. For PowerSaver processors we can't depend on Max / MinMHzFSB because these values are only used for PowerSaver 2.0 and 3.0. Most processors on which Longhaul is used are PowerSaver 1.0 only. I'm changing code for older CPU's too, but not so much as previously, and this code was already used for Ezra. Using MinMHzBR for Ezra-T is outside spec. It is for voltage scaling purpose and don't have to be equal to minmult (but it is). Same for Nehemiah (it isn't for sure). Added mult - current multiplier value. Signed-off-by: Rafał Bilski <rafalbilski@interia.pl> Signed-off-by: Dave Jones <davej@redhat.com>
-rw-r--r--arch/i386/kernel/cpu/cpufreq/longhaul.c44
1 files changed, 14 insertions, 30 deletions
diff --git a/arch/i386/kernel/cpu/cpufreq/longhaul.c b/arch/i386/kernel/cpu/cpufreq/longhaul.c
index fd70c77acc1..f152c291e7c 100644
--- a/arch/i386/kernel/cpu/cpufreq/longhaul.c
+++ b/arch/i386/kernel/cpu/cpufreq/longhaul.c
@@ -318,12 +318,12 @@ static void longhaul_setstate(unsigned int clock_ratio_index)
#define ROUNDING 0xf
-static int _guess(int guess)
+static int _guess(int guess, int mult)
{
int target;
- target = ((maxmult/10)*guess);
- if (maxmult%10 != 0)
+ target = ((mult/10)*guess);
+ if (mult%10 != 0)
target += (guess/2);
target += ROUNDING/2;
target &= ~ROUNDING;
@@ -331,17 +331,17 @@ static int _guess(int guess)
}
-static int guess_fsb(void)
+static int guess_fsb(int mult)
{
int speed = (cpu_khz/1000);
int i;
- int speeds[3] = { 66, 100, 133 };
+ int speeds[] = { 66, 100, 133, 200 };
speed += ROUNDING/2;
speed &= ~ROUNDING;
- for (i=0; i<3; i++) {
- if (_guess(speeds[i]) == speed)
+ for (i=0; i<4; i++) {
+ if (_guess(speeds[i], mult) == speed)
return speeds[i];
}
return 0;
@@ -361,6 +361,7 @@ static int __init longhaul_get_ranges(void)
unsigned long lo, hi;
unsigned int eblcr_fsb_table_v1[] = { 66, 133, 100, -1 };
unsigned int eblcr_fsb_table_v2[] = { 133, 100, -1, 66 };
+ int mult;
switch (longhaul_version) {
case TYPE_LONGHAUL_V1:
@@ -368,30 +369,18 @@ static int __init longhaul_get_ranges(void)
/* Ugh, Longhaul v1 didn't have the min/max MSRs.
Assume min=3.0x & max = whatever we booted at. */
minmult = 30;
- maxmult = longhaul_get_cpu_mult();
- rdmsr (MSR_IA32_EBL_CR_POWERON, lo, hi);
- invalue = (lo & (1<<18|1<<19)) >>18;
- if (cpu_model==CPU_SAMUEL || cpu_model==CPU_SAMUEL2)
- fsb = eblcr_fsb_table_v1[invalue];
- else
- fsb = guess_fsb();
+ maxmult = mult = longhaul_get_cpu_mult();
break;
case TYPE_POWERSAVER:
/* Ezra-T */
if (cpu_model==CPU_EZRA_T) {
+ minmult = 30;
rdmsrl (MSR_VIA_LONGHAUL, longhaul.val);
invalue = longhaul.bits.MaxMHzBR;
if (longhaul.bits.MaxMHzBR4)
invalue += 16;
- maxmult=ezra_t_multipliers[invalue];
-
- invalue = longhaul.bits.MinMHzBR;
- if (longhaul.bits.MinMHzBR4 == 1)
- minmult = 30;
- else
- minmult = ezra_t_multipliers[invalue];
- fsb = eblcr_fsb_table_v2[longhaul.bits.MaxMHzFSB];
+ maxmult = mult = ezra_t_multipliers[invalue];
break;
}
@@ -411,21 +400,16 @@ static int __init longhaul_get_ranges(void)
* But it works, so we don't grumble.
*/
minmult=40;
- maxmult=longhaul_get_cpu_mult();
-
- /* Starting with the 1.2GHz parts, theres a 200MHz bus. */
- if ((cpu_khz/maxmult) > 13400)
- fsb = 200;
- else
- fsb = eblcr_fsb_table_v2[longhaul.bits.MaxMHzFSB];
+ maxmult = mult = longhaul_get_cpu_mult();
break;
}
}
+ fsb = guess_fsb(mult);
dprintk ("MinMult:%d.%dx MaxMult:%d.%dx\n",
minmult/10, minmult%10, maxmult/10, maxmult%10);
- if (fsb == -1) {
+ if (fsb == 0) {
printk (KERN_INFO PFX "Invalid (reserved) FSB!\n");
return -EINVAL;
}