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| author |   Mattia Dongili <malattia@linux.it> | 2005-12-02 21:59:41 +0100 |
|---|---|---|
| committer |   Dave Jones <davej@redhat.com> | 2005-12-06 19:27:15 -0800 |
| commit | 1a10760c91c394dfe4adfefeeaf85cd8098c4894 (patch) | |
| tree | 80e6bfa8c8c247843bfbc90b9809ffafda1841f8 /arch/i386/kernel/cpu/cpufreq/speedstep-ich.c | |
| parent | Merge ../linus/ (diff) | |
| download | linux-dev-1a10760c91c394dfe4adfefeeaf85cd8098c4894.tar.xz linux-dev-1a10760c91c394dfe4adfefeeaf85cd8098c4894.zip | |
[CPUFREQ] Measure transition latency at driver initialization
The attached patch introduces runtime latency measurement for ICH[234]
based chipsets instead of using CPUFREQ_ETERNAL. It includes
some sanity checks in case the measured value is out of range and
assigns a safe value of 500uSec that should still be enough on
problematics chipsets (current testing report values ~200uSec). The
measurement is currently done in speedstep_get_freqs in order to avoid
further unnecessary transitions and in the hope it'll come handy for SMI
also.
Signed-off-by: Mattia Dongili <malattia@linux.it>
Acked-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Dave Jones <davej@redhat.com>
speedstep-ich.c | 4 ++--
speedstep-lib.c | 32 +++++++++++++++++++++++++++++++-
speedstep-lib.h | 1 +
speedstep-smi.c | 1 +
4 files changed, 35 insertions(+), 3 deletions(-)
Diffstat (limited to 'arch/i386/kernel/cpu/cpufreq/speedstep-ich.c')
| -rw-r--r-- | arch/i386/kernel/cpu/cpufreq/speedstep-ich.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/i386/kernel/cpu/cpufreq/speedstep-ich.c b/arch/i386/kernel/cpu/cpufreq/speedstep-ich.c index 5b7d18a06afa..862e0b5656b9 100644 --- a/arch/i386/kernel/cpu/cpufreq/speedstep-ich.c +++ b/arch/i386/kernel/cpu/cpufreq/speedstep-ich.c @@ -315,10 +315,11 @@ static int speedstep_cpu_init(struct cpufreq_policy *policy) cpus_allowed = current->cpus_allowed; set_cpus_allowed(current, policy->cpus); - /* detect low and high frequency */ + /* detect low and high frequency and transition latency */ result = speedstep_get_freqs(speedstep_processor, &speedstep_freqs[SPEEDSTEP_LOW].frequency, &speedstep_freqs[SPEEDSTEP_HIGH].frequency, + &policy->cpuinfo.transition_latency, &speedstep_set_state); set_cpus_allowed(current, cpus_allowed); if (result) @@ -335,7 +336,6 @@ static int speedstep_cpu_init(struct cpufreq_policy *policy) /* cpuinfo and default policy values */ policy->governor = CPUFREQ_DEFAULT_GOVERNOR; - policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; policy->cur = speed; result = cpufreq_frequency_table_cpuinfo(policy, speedstep_freqs); |