| From 4042e7570cff740460b75c6fc604c629621d3dd2 Mon Sep 17 00:00:00 2001 |
| From: Dirk Brandewie <dirk.j.brandewie@intel.com> |
| Date: Wed, 12 Feb 2014 10:01:06 -0800 |
| Subject: intel_pstate: Use LFM bus ratio as min ratio/P state |
| |
| From: Dirk Brandewie <dirk.j.brandewie@intel.com> |
| |
| commit 4042e7570cff740460b75c6fc604c629621d3dd2 upstream. |
| |
| LFM (max efficiency ratio) is the max frequency at minimum voltage |
| supported by the processor. Using LFM as the minimum P state |
| increases performmance without affecting power. By not using P states |
| below LFM we avoid using P states that are less power efficient. |
| |
| Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com> |
| Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/cpufreq/intel_pstate.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- a/drivers/cpufreq/intel_pstate.c |
| +++ b/drivers/cpufreq/intel_pstate.c |
| @@ -348,7 +348,7 @@ static int byt_get_min_pstate(void) |
| { |
| u64 value; |
| rdmsrl(BYT_RATIOS, value); |
| - return value & 0xFF; |
| + return (value >> 8) & 0xFF; |
| } |
| |
| static int byt_get_max_pstate(void) |
