[CPUFREQ] powernow-k8: Limit Pstate transition latency check

The Pstate transition latency check was added for broken F10h BIOSen
which wrongly contain a value of 0 for transition and bus master
latency. Fam11h and later, however, (will) have similar transition
latency so extend that behavior for them too.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Dave Jones <davej@redhat.com>

1 files changed, 5 insertions, 6 deletions

diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
index 7ec2123838e..3e90cce3dc8 100644
--- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
+++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
@@ -1023,13 +1023,12 @@ static int get_transition_latency(struct powernow_k8_data *data)
         }
         if (max_latency == 0) {
                 /*
-                 * Fam 11h always returns 0 as transition latency.
-                 * This is intended and means "very fast". While cpufreq core
-                 * and governors currently can handle that gracefully, better
-                 * set it to 1 to avoid problems in the future.
-                 * For all others it's a BIOS bug.
+                 * Fam 11h and later may return 0 as transition latency. This
+                 * is intended and means "very fast". While cpufreq core and
+                 * governors currently can handle that gracefully, better set it
+                 * to 1 to avoid problems in the future.
                  */
-                if (boot_cpu_data.x86 != 0x11)
+                if (boot_cpu_data.x86 < 0x11)
                         printk(KERN_ERR FW_WARN PFX "Invalid zero transition "
                                 "latency\n");
                 max_latency = 1;