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  Testing suspend and resume support in device drivers

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  	(C) 2007 Rafael J. Wysocki <rjw@sisk.pl>, GPL
  
  1. Preparing the test system

  ============================

  
  Unfortunately, to effectively test the support for the system-wide suspend and
  resume transitions in a driver, it is necessary to suspend and resume a fully
  functional system with this driver loaded.  Moreover, that should be done

  several times, preferably several times in a row, and separately for hibernation
  (aka suspend to disk or STD) and suspend to RAM (STR), because each of these
  cases involves slightly different operations and different interactions with

  the machine's BIOS.
  
  Of course, for this purpose the test system has to be known to suspend and
  resume without the driver being tested.  Thus, if possible, you should first
  resolve all suspend/resume-related problems in the test system before you start

  testing the new driver.  Please see Documentation/power/basic-pm-debugging.rst

  for more information about the debugging of suspend/resume functionality.

  
  2. Testing the driver

  =====================

  
  Once you have resolved the suspend/resume-related problems with your test system
  without the new driver, you are ready to test it:

  a) Build the driver as a module, load it and try the test modes of hibernation

     (see: Documentation/power/basic-pm-debugging.rst, 1).

  b) Load the driver and attempt to hibernate in the "reboot", "shutdown" and

     "platform" modes (see: Documentation/power/basic-pm-debugging.rst, 1).

  c) Compile the driver directly into the kernel and try the test modes of
     hibernation.

  d) Attempt to hibernate with the driver compiled directly into the kernel
     in the "reboot", "shutdown" and "platform" modes.

  e) Try the test modes of suspend (see:
     Documentation/power/basic-pm-debugging.rst, 2).  [As far as the STR tests are
     concerned, it should not matter whether or not the driver is built as a
     module.]

  
  f) Attempt to suspend to RAM using the s2ram tool with the driver loaded

     (see: Documentation/power/basic-pm-debugging.rst, 2).

  
  Each of the above tests should be repeated several times and the STD tests
  should be mixed with the STR tests.  If any of them fails, the driver cannot be
  regarded as suspend/resume-safe.