This doesn't fix anything, but it's expected that a transition latency of 0
could cause trouble in the future.
Signed-off-by: Thomas Renninger <trenn@xxxxxxx>
Cc: Langsdorf, Mark <mark.langsdorf@xxxxxxx>
---
arch/x86/kernel/cpu/cpufreq/powernow-k8.c | 13 +++++++++++++
1 files changed, 13 insertions(+), 0 deletions(-)
diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
index 4709ead..f023506 100644
--- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
+++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
@@ -1026,6 +1026,19 @@ static int get_transition_latency(struct powernow_k8_data *data)
if (cur_latency > max_latency)
max_latency = cur_latency;
}
+ 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.
+ */
+ if (!boot_cpu_data.x86 == 0x11)
+ printk (KERN_ERR FW_WARN PFX "Invalid zero transition "
+ "latency\n");
+ max_latency = 1;
+ }
/* value in usecs, needs to be in nanoseconds */
return 1000 * max_latency;
}
--
1.6.0.2
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