[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>

1 files changed, 9 insertions, 0 deletions

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;
         }