From: Zhang Rui Date: Thu, 17 Jan 2008 07:51:23 +0000 (+0800) Subject: ACPI: register ACPI Processor as generic thermal cooling device X-Git-Tag: v2.6.25-rc1~297^2~3^2~2^2~1^3~6 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d9460fd227ed2ce52941b6a12ad4de05c195f6aa;p=pandora-kernel.git ACPI: register ACPI Processor as generic thermal cooling device Register ACPI processor as thermal cooling devices. A combination of processor T-state and P-state are used for thermal throttling. the processor will reduce the frequency first and then set the T-state. we use cpufreq_thermal_reduction_pctg to calculate the cpufreq limit, and call cpufreq_verify_with_limit to set the cpufreq limit. if cpufreq driver is loaded, then we have four cooling state for cpufreq control. cooling state 0: cpufreq limit == max_freq cooling state 1: cpufreq limit == max_freq * 80% cooling state 2: cpufreq limit == max_freq * 60% cooling state 3: cpufreq limit == max_freq * 40% after the cpufreq limit is set to 40 percentage of the max_freq, we use T-state for cooling. eg. a processor has P-state support, and it has 8 T-state (T0-T7), the max_state of the proceesor is 10: state cpufreq-limit T-state 0: max_freq T0 1: max_freq * 80% T0 2: max_freq * 60% T0 3: max_freq * 40% T0 4: max_freq * 40% T1 5: max_freq * 40% T2 6: max_freq * 40% T3 7: max_freq * 40% T4 8: max_freq * 40% T5 9: max_freq * 40% T6 10: max_freq * 40% T7 Signed-off-by: Zhang Rui Signed-off-by: Zhao Yakui Signed-off-by: Thomas Sujith Signed-off-by: Len Brown --- Reading git-diff-tree failed