[CPUFREQ] powernow-k8: Limit Pstate transition latency check
Borislav Petkov [Thu, 8 Jul 2010 15:55:30 +0000 (17:55 +0200)]
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>

arch/x86/kernel/cpu/cpufreq/powernow-k8.c

index 7ec2123..3e90cce 100644 (file)
@@ -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;