From 46ef955f5c9de0507859a3f9a92989b7425b73cc Mon Sep 17 00:00:00 2001 From: =?utf8?q?Rafa=B3=20Bilski?= Date: Sun, 4 Feb 2007 15:58:46 +0100 Subject: [PATCH] [CPUFREQ] Longhaul - Fix guess_fsb function This is bug reported by John-Marc Chandonia: > Detected 1002.292 MHz processor. > longhaul: VIA C3 'Nehemiah B' [C5N] CPU detected. Powersaver supported. > longhaul: Using throttling support. > longhaul: Invalid (reserved) FSB! FSB is correcly guessed for 999.554 MHz CPU. To fix this error: - ROUNDING should be range, not mask - at it's current value it is +7 -8, - more precise calculations inside guess_fsb - 7.5x133MHz is 1000MHz now. Signed-off-by: Rafal Bilski Signed-off-by: Dave Jones --- arch/i386/kernel/cpu/cpufreq/longhaul.c | 32 ++++++++++---------------------- 1 file changed, 10 insertions(+), 22 deletions(-) diff --git a/arch/i386/kernel/cpu/cpufreq/longhaul.c b/arch/i386/kernel/cpu/cpufreq/longhaul.c index 8ea34e9..8b5ad30 100644 --- a/arch/i386/kernel/cpu/cpufreq/longhaul.c +++ b/arch/i386/kernel/cpu/cpufreq/longhaul.c @@ -318,31 +318,19 @@ static void longhaul_setstate(unsigned int clock_ratio_index) #define ROUNDING 0xf -static int _guess(int guess, int mult) -{ - int target; - - target = ((mult/10)*guess); - if (mult%10 != 0) - target += (guess/2); - target += ROUNDING/2; - target &= ~ROUNDING; - return target; -} - - static int guess_fsb(int mult) { - int speed = (cpu_khz/1000); + int speed = cpu_khz / 1000; int i; - int speeds[] = { 66, 100, 133, 200 }; - - speed += ROUNDING/2; - speed &= ~ROUNDING; - - for (i=0; i<4; i++) { - if (_guess(speeds[i], mult) == speed) - return speeds[i]; + int speeds[] = { 666, 1000, 1333, 2000 }; + int f_max, f_min; + + for (i = 0; i < 4; i++) { + f_max = ((speeds[i] * mult) + 50) / 100; + f_max += (ROUNDING / 2); + f_min = f_max - ROUNDING; + if ((speed <= f_max) && (speed >= f_min)) + return speeds[i] / 10; } return 0; } -- 2.7.4