[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 270f218..cc73a7a 100644
--- a/arch/i386/kernel/cpu/cpufreq/p4-clockmod.c
+++ b/arch/i386/kernel/cpu/cpufreq/p4-clockmod.c
@@ -52,6 +52,7 @@
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 @@
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 @@
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;
}