From c70ca00f77eb1bb69c5a2d029b3a911bc88eac1b Mon Sep 17 00:00:00 2001 From: Ben Collins Date: Wed, 18 Jan 2006 23:45:39 -0800 Subject: [PATCH] [CPUFREQ] p4-clockmod: Workaround for CPU's with N60 errata Ignore clock frequencies below 2Ghz for CPU's detected with N60 errata bug. Signed-off-by: Ben Collins Signed-off-by: Andrew Morton Signed-off-by: Dave Jones --- arch/i386/kernel/cpu/cpufreq/p4-clockmod.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/i386/kernel/cpu/cpufreq/p4-clockmod.c b/arch/i386/kernel/cpu/cpufreq/p4-clockmod.c index 270f2188d68b..cc73a7ae34bc 100644 --- a/arch/i386/kernel/cpu/cpufreq/p4-clockmod.c +++ b/arch/i386/kernel/cpu/cpufreq/p4-clockmod.c @@ -52,6 +52,7 @@ enum { static int has_N44_O17_errata[NR_CPUS]; +static int has_N60_errata[NR_CPUS]; static unsigned int stock_freq; static struct cpufreq_driver p4clockmod_driver; static unsigned int cpufreq_p4_get(unsigned int cpu); @@ -226,6 +227,12 @@ static int cpufreq_p4_cpu_init(struct cpufreq_policy *policy) case 0x0f12: has_N44_O17_errata[policy->cpu] = 1; dprintk("has errata -- disabling low frequencies\n"); + break; + + case 0x0f29: + has_N60_errata[policy->cpu] = 1; + dprintk("has errata -- disabling frequencies lower than 2ghz\n"); + break; } /* get max frequency */ @@ -237,6 +244,8 @@ static int cpufreq_p4_cpu_init(struct cpufreq_policy *policy) for (i=1; (p4clockmod_table[i].frequency != CPUFREQ_TABLE_END); i++) { if ((i<2) && (has_N44_O17_errata[policy->cpu])) p4clockmod_table[i].frequency = CPUFREQ_ENTRY_INVALID; + else if (has_N60_errata[policy->cpu] && p4clockmod_table[i].frequency < 2000000) + p4clockmod_table[i].frequency = CPUFREQ_ENTRY_INVALID; else p4clockmod_table[i].frequency = (stock_freq * i)/8; }