[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 <bcollins@ubuntu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Dave Jones <davej@redhat.com>

diff --git a/arch/i386/kernel/cpu/cpufreq/p4-clockmod.c b/arch/i386/kernel/cpu/cpufreq/p4-clockmod.c
index 270f2188d68b1857d3ef59c3a71adf7f106de2c4..cc73a7ae34bc3f92f7177bd606b698bcc192e28b 100644 (file)
--- 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;
        }