Provided by: powersaved_0.12.15-0ubuntu1_i386 bug

NAME

       powersave - get/set power saving states of the machine, influence power
       management

SYNOPSIS

       powersave {-f|-l|-A} {-u|-U|-m} -[crbBsSaTFVtx] [-p percent] [-v level]
       [-e scheme_name] [ options ]

DESCRIPTION

       powersave  provides  a  command  line interface to various power saving
       related functionalities of your machine.  Powersave supports APM,  ACPI
       and  cpu-frequency  scaling (speedstep, powernow, ...) features as well
       as some ide disk power saving  functionalities.   Take  care  that  the
       appropriate  modules  for  the  features  you want to use are loaded or
       compiled into the kernel.  Some options may work  correctly  only  with
       the  latest kernels.  Some options are quite hardware dependent and you
       should be able to test their support by using this tool.  For automatic
       global  power  management please install and start the powersave daemon
       on your system.  Once you started the daemon you should  only  use  the
       powersave  daemon  depending  functions or functions which just provide
       information about the  system.   The  cpufreq  control  functions  like
       performance-,  powersave-,  dynamic-speed  are  used  by  the powersave
       daemon. You may want to use them, but remember  that  powersave  policy
       should  be  configured in the configuration files and your settings may
       be overridden by the daemon.

OPTIONS THAT NEED A RUNNING POWERSAVE DAEMON

       Be aware that the powersave system group exists and that users  allowed
       to use these functions are part of the powersave group.

       --suspend-to-disk -U
              Sets  the  machine  into  suspend  (APM) or S4/"Suspend to Disk"
              (ACPI) mode

       --suspend-to-ram -u
              Sets the machine into  suspend  (APM)  or  S3/"Suspend  to  RAM"
              (ACPI) mode

       --standby -m
              Sets the machine into standby (APM) or S1/"Standby" (ACPI) mode

       --performance-speed -f
              Makes  the  daemon  to  set the machine fixed to the the highest
              supported frequency.  This option needs your hardware to support
              CPU frequency scaling (SpeedStep/PowerNow).

       --powersave-speed -l
              Makes  the  daemon  to  set  the  machine  fixed  to  the lowest
              supported frequency.

       --dynamic-speed -A
              Makes the  daemon  to  adjust  the  frequency  of  your  machine
              dynamically.  This is always a good solution (for battery and AC
              plugged in).  It saves a lot of power and reduces the  noise  of
              your  fan (if controlled).  You should not recognise any loss of
              performance.

       --ondemand-speed -o
              Gives cpufreq control to the kernel. The kernel will adjust  the
              speed/frequency  instead  of  the  daemon. This is known to have
              slightly better  performance  values,  but  mostly  worse  power
              saving  results  (depending  on  the  configs  which also behave
              slightly different). It’s also known as not that field tested as
              the dynamic-speed setting.

       --cpufreq-state -c
              Asks the daemon for the current cpufrequency scaling method:

       battery-state -s
              Asks  the daemon for the current battery state: NORMAL, WARNING,
              LOW or CRITICAL.

OPTIONS THAT NEED ACPI WORKING AND THE APPROPRIATE KERNEL MODULES LOADED

       --set-throttling-percent -p
              Evaluates how much throttling states your machine  supports  and
              sets  the  appropriate  state  according  to your value.  Please
              specify the value in percent you want to throttle  the  CPU.   A
              value of 0 means no throttling, maximum CPU power.  Avoid values
              higher than 80%, because this could easily freeze your  machine!
              You  need  superuser  rights  for  this  option.   This  funtion
              throttles all CPUs of your machine.

       --get-throttling-info -t
              Prints out the current and available throttling  state  of  each
              CPU in the system.

       --apm-acpi -S
              Evaluates whether your system supports APM or ACPI.

       --battery-info -b
              Prints  out  remaining battery capacity in percent and remaining
              lifetime  of  battery.  Remaining  lifetime  should  only   give
              sensible  values  when  working on battery power source.  It may
              happen that the remaining life time cannot be  read  immediately
              after  switching  to  battery  power,  try  it  again after some
              seconds.   Depending  whether  your  BIOS  is  buggy   remaining
              lifetime  or  even  remaining  percent  can  not  be calculated.
              Multiple batteries will be sumerized to a total.

       --extended-battery-info -B
              Prints out remaining battery capacity in percent  and  remaining
              lifetime  for  each  battery.  This  only  works  if your system
              supports ACPI

       ac-status-info -a
              Evaluate whether  AC  adapter  is  plugged  in  or  if  you  are
              currently working on battery power.

       get-thermal-info -T
              iterates   available   thermal   devices   and   prints  current
              temperature and defined trippoints

       get-fan-info -F
              detects which fan is on/off

       list-schemes -x
              List all power schemes. Also shows  which  one  is  the  current
              active one and which are activated if power source changes to AC
              or battery  power.   Configuration  files  for  schemes  are  by
              default located in /etc/powersave/scheme_*. A scheme changes the
              power save policy of the powersave daemon.  Changing  the  power
              source  (AC/Battery)  normally switches the power policy/scheme.
              Use -e option to switch between schemes manually.

       get-scheme-description -X
              Show the description of a scheme.

       set-active-scheme -e
              See above. Use -x to list all schemes you can switch to.

       get-brightness -K
              Get the current brightness level of the  display  if  supported.
              This  works  at  the  moment  with  many  toshiba, sony and asus
              notebooks.

       get-brightness-levels -L
              Get number of supported brightness levels.

       set-brightness -k
              Set the  current  brightness  level.  Get  abailable  brightness
              levels  with  -L  or  give  character ’u’ for "brightness up" or
              character ’d’ for "brightness down"

GENERAL OPTIONS - NEED NO KERNEL MODULS OR A RUNNING POWERSAVE DAEMON

       --verbose -v
              Set the debug level, allowed values: 0-31 Depending on  how  the
              binary  was  compiled  the output is written to stdout/stderr or
              directly forwarded to the syslog  daemon  (default)  or  totally
              discarded.   So  you  normally should check /var/log/messages to
              check for errors 1  Error 2  Warning 4  Diag 8   Info  16  Debug
              e.g.  Error + Warning: 1 + 2 -> 3

       --version -V
              prints the current compiled version of the package

       --calc-CPU-frequency -r
              prints  out  the  current CPU frequency of the machine using the
              time stamp counter (tsc) register This should be a similar value
              as  in  /proc/cpuinfo, however the value there could be wrong if
              you encounter a kernel bug.  If you  are  fiddling  around  with
              SpeedStep  or  PowerNow  you  should  rely  on  this value; This
              currently only works on some single  processor  machines  (i686,
              x86_64)

RETURN VALUES

       All options return 0 on success and any other value on failure.

       Except:

       --apm-acpi  -S  returns  -1 if it fails, 2 for an APM machine and 1 for
       ACPI support!

       --ac-status-info -a returns -1 if it fails, 2 for on AC and  1  for  on
       battery power!

       --cpufreq-state  -c  returns  1  if  system  is  in  maximum  frequency
       (performance) mode, 2 if system is  in  minimum  frequency  (powersave)
       mode  and  3  if  frequency is adjusted depending on CPU usage (dynamic
       mode)

       --battery-state, returns 1 if battery is  in  normal  state,  2  if  in
       warning, 3 if in low and 4 if battery is in critical state

       This might change when using multiple options at once (see next).

MULTIPLE OPTIONS

       Several  parameters  can be passed at once.  The order of the output of
       each parameter complies to the order as  listed  above.   If  an  error
       occurs,  the  return value will be EXIT_FAILURE(1), or lower than zero.
       If no error occured the return value will 0.  If  a  parameter  with  a
       special return value (see above) is used zero will be overridden
        with  the  meaning  described  above.   If  several  parameters with a
       special return value are passed,  the  last  listed  parameter  with  a
       special return value will represent the return value.

ACCESS TO DAEMON

       This  section affects parameters stated above under OPTIONS THAT NEED A
       RUNNING POWERSAVE DAEMON.  The connect is done by a UNIX  socket.   Who
       is allowed to connect and query the daemon is passed to the daemon when
       the daemon is started.  This is in  the  /etc/init.d/powersaved  script
       and is done with the -a parameter.  (see manpage of powersaved).

BUGS

       calculating  frequency  could  be wrong if processor is in higher power
       save (C-)states (C3 and above normally). This is normal.

AUTHOR

       powersave has been written by Thomas Renninger <mail@renninger.de>

       Inspiration and code  parts  partly  come  from  the  acpid,  apmd  and
       cpufreqd  packages.  Many thanks to all developers who helped to create
       this software.

SEE ALSO

       powersaved(8)

       ACPI kernel modules: ac, battery, button, thermal, processor, fan

       cpufreq      kernel       modules,       see       kernel       sources
       /usr/src/linux/Documentation/cpu-freq