This file documents NVIDIA Tegra specific sysfs and debugfs files and kernel module parameters. /sys/power/suspend/mode ----------------------- Used to select the LP1 or LP0 power state during system suspend. # echo lp0 > /sys/kernel/debug/suspend_mode # echo lp1 > /sys/kernel/debug/suspend_mode /sys/module/cpuidle/parameters/lp2_in_idle ------------------------------------------ Used to enable/disable LP2 in idle. # echo 1 > /sys/module/cpuidle/parameters/lp2_in_idle # echo 0 > /sys/module/cpuidle/parameters/lp2_in_idle /sys/kernel/debug/cpuidle/lp2 ----------------------------- Contains LP2 statistics. # cat /sys/kernel/debug/cpuidle/lp2 /sys/kernel/debug/powergate --------------------------- Contains power gating state of different tegra blocks. # cat /sys/kernel/debug/powergate /sys/module/cpu_tegra3/parameters/auto_hotplug ---------------------------------------------- Used to control auto hotplug governor # echo 0 >/sys/module/cpu_tegra3/parameters/auto_hotplug # echo 1 >/sys/module/cpu_tegra3/parameters/auto_hotplug # cat /sys/module/cpu_tegra3/parameters/auto_hotplug 0: disabled 1: idle 2: down 3: up /sys/module/cpu_tegra3/parameters/no_lp --------------------------------------- Used to enable/disable shadow cluster. # echo 0 >/sys/module/cpu_tegra3/parameters/no_lp # echo 1 >/sys/module/cpu_tegra3/parameters/no_lp /sys/module/cpu_tegra3/parameters/idle_bottom_freq -------------------------------------------------- Shadow cluster maximum frequency. /sys/module/cpu_tegra3/parameters/idle_top_freq ----------------------------------------------- Main cluster minimum frequency. /sys/module/cpu_tegra3/parameters/down_delay --------------------------------------------- Auto hotplug delay (in jiffies) for reducing cores. /sys/module/cpu_tegra3/parameters/up2g0_delay --------------------------------------------- Delay (in jiffies) for swithing to main cluster. /sys/module/cpu_tegra3/parameters/up2gn_delay --------------------------------------------- Delay (in jiffies) for bringing additional cores online in main cluster. /sys/module/cpu_tegra3/parameters/balance_level ----------------------------------------------- Percentage of max speed considered to be in balance. Half of balanced speed is considered skewed. Speed balance states: * balanced: freq targets for all CPUs are above 50% of highest speed * biased: freq target for at least one CPU is below 50% threshold * skewed: freq targets for at least 2 CPUs are below 25% threshold Speed balance state and hotplug state dictates auto hotlug behavior. /sys/module/cpu_tegra3/parameters/mp_overhead --------------------------------------------- Multi-core overhead percentage for EDP limit calculation. /sys/kernel/debug/tegra_hotplug/stats ------------------------------------- Contains hotplug statistics. /sys/kernel/cluster/active -------------------------- Controls active CPU cluster: main (G) or shadow (LP). For manual control disable auto hotlug, enable immediate switch and possibly force switch to happen always: # echo 0 > /sys/module/cpu_tegra3/parameters/auto_hotplug # echo 1 > /sys/kernel/cluster/immediate # echo 1 > /sys/kernel/cluster/force Cluster switching can happen only when only core 0 is online. Active cluster can be set or toggled: # echo "G" > /sys/kernel/cluster/active # echo "LP" > /sys/kernel/cluster/active # echo "toggle" > /sys/kernel/cluster/active /sys/module/tegra3_clocks/parameters/detach_shared_bus ------------------------------------------------------ Enable/disable shared bus clock update. /sys/module/tegra3_emc/parameters/emc_enable -------------------------------------------- Enable/disable EMC DFS. /sys/kernel/debug/tegra_emc/stats --------------------------------- Contains EMC clock statistics. /sys/module/tegra3_dvfs/parameters/disable_cpu ---------------------------------------------- Enable/disable DVFS for CPU domain. /sys/module/tegra3_dvfs/parameters/disable_core ----------------------------------------------- Enable/disable DVFS for CORE domain. /sys/kernel/debug/clock/emc/rate -------------------------------- Get/set EMC clock rate. /sys/kernel/debug/clock//rate ------------------------------------- /sys/kernel/debug/clock//parent --------------------------------------- /sys/kernel/debug/clock//state -------------------------------------- /sys/kernel/debug/clock//time_on ---------------------------------------- /sys/kernel/debug/clock/clock_tree ---------------------------------- Shows the state of the clock tree. /sys/kernel/debug/clock/dvfs ---------------------------- Contains voltage state. /sys/kernel/debug/tegra_actmon/avp/state ---------------------------------------- /sys/kernel/debug/clock/mon.avp/rate ------------------------------------ /sys/kernel/debug/clock/rails ----------------------------- Contains the time at each voltage. /sys/devices/system/cpu/cpu0/cpufreq/stats/time_in_state -------------------------------------------------------- Contains the time at each frequency.