1Testing suspend and resume support in device drivers 2 (C) 2007 Rafael J. Wysocki <rjw@sisk.pl>, GPL 3 41. Preparing the test system 5 6Unfortunately, to effectively test the support for the system-wide suspend and 7resume transitions in a driver, it is necessary to suspend and resume a fully 8functional system with this driver loaded. Moreover, that should be done 9several times, preferably several times in a row, and separately for hibernation 10(aka suspend to disk or STD) and suspend to RAM (STR), because each of these 11cases involves slightly different operations and different interactions with 12the machine's BIOS. 13 14Of course, for this purpose the test system has to be known to suspend and 15resume without the driver being tested. Thus, if possible, you should first 16resolve all suspend/resume-related problems in the test system before you start 17testing the new driver. Please see Documentation/power/basic-pm-debugging.txt 18for more information about the debugging of suspend/resume functionality. 19 202. Testing the driver 21 22Once you have resolved the suspend/resume-related problems with your test system 23without the new driver, you are ready to test it: 24 25a) Build the driver as a module, load it and try the test modes of hibernation 26 (see: Documents/power/basic-pm-debugging.txt, 1). 27 28b) Load the driver and attempt to hibernate in the "reboot", "shutdown" and 29 "platform" modes (see: Documents/power/basic-pm-debugging.txt, 1). 30 31c) Compile the driver directly into the kernel and try the test modes of 32 hibernation. 33 34d) Attempt to hibernate with the driver compiled directly into the kernel 35 in the "reboot", "shutdown" and "platform" modes. 36 37e) Try the test modes of suspend (see: Documents/power/basic-pm-debugging.txt, 38 2). [As far as the STR tests are concerned, it should not matter whether or 39 not the driver is built as a module.] 40 41f) Attempt to suspend to RAM using the s2ram tool with the driver loaded 42 (see: Documents/power/basic-pm-debugging.txt, 2). 43 44Each of the above tests should be repeated several times and the STD tests 45should be mixed with the STR tests. If any of them fails, the driver cannot be 46regarded as suspend/resume-safe. 47