From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Renninger Subject: [PATCH] cpufreq powernow-k8: Remove firmware warning in zero transition latency case Date: Wed, 8 Jun 2011 10:07:13 +0200 Message-ID: <201106081007.14264.trenn@suse.de> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: Sender: cpufreq-owner@vger.kernel.org List-ID: Content-Type: Text/Plain; charset="us-ascii" To: davej@codemonkey.org.uk Cc: cpufreq@vger.kernel.org AMD's BKDG documents that a zero transition latency should get passed for several recent CPU models. -> This isn't a firmware bug. I did not dare to really pass the zero latency to the cpufreq core, this would need careful checking whether this does not show side effects. -> Still modify latency to 1 (us) in case BIOS passes zero. Signed-off-by: Thomas Renninger CC: cpufreq@vger.kernel.org CC: davej@codemonkey.org.uk --- drivers/cpufreq/powernow-k8.c | 13 ++----------- 1 files changed, 2 insertions(+), 11 deletions(-) diff --git a/drivers/cpufreq/powernow-k8.c b/drivers/cpufreq/powernow-k8.c index 83479b6..170ad36 100644 --- a/drivers/cpufreq/powernow-k8.c +++ b/drivers/cpufreq/powernow-k8.c @@ -1022,18 +1022,9 @@ 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 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) - printk(KERN_ERR FW_WARN PFX "Invalid zero transition " - "latency\n"); + if (max_latency == 0) max_latency = 1; - } + /* value in usecs, needs to be in nanoseconds */ return 1000 * max_latency; }