1==================================================== 2Testing suspend and resume support in device drivers 3==================================================== 4 5 (C) 2007 Rafael J. Wysocki <rjw@sisk.pl>, GPL 6 71. Preparing the test system 8============================ 9 10Unfortunately, to effectively test the support for the system-wide suspend and 11resume transitions in a driver, it is necessary to suspend and resume a fully 12functional system with this driver loaded. Moreover, that should be done 13several times, preferably several times in a row, and separately for hibernation 14(aka suspend to disk or STD) and suspend to RAM (STR), because each of these 15cases involves slightly different operations and different interactions with 16the machine's BIOS. 17 18Of course, for this purpose the test system has to be known to suspend and 19resume without the driver being tested. Thus, if possible, you should first 20resolve all suspend/resume-related problems in the test system before you start 21testing the new driver. Please see Documentation/power/basic-pm-debugging.rst 22for more information about the debugging of suspend/resume functionality. 23 242. Testing the driver 25===================== 26 27Once you have resolved the suspend/resume-related problems with your test system 28without the new driver, you are ready to test it: 29 30a) Build the driver as a module, load it and try the test modes of hibernation 31 (see: Documentation/power/basic-pm-debugging.rst, 1). 32 33b) Load the driver and attempt to hibernate in the "reboot", "shutdown" and 34 "platform" modes (see: Documentation/power/basic-pm-debugging.rst, 1). 35 36c) Compile the driver directly into the kernel and try the test modes of 37 hibernation. 38 39d) Attempt to hibernate with the driver compiled directly into the kernel 40 in the "reboot", "shutdown" and "platform" modes. 41 42e) Try the test modes of suspend (see: 43 Documentation/power/basic-pm-debugging.rst, 2). [As far as the STR tests are 44 concerned, it should not matter whether or not the driver is built as a 45 module.] 46 47f) Attempt to suspend to RAM using the s2ram tool with the driver loaded 48 (see: Documentation/power/basic-pm-debugging.rst, 2). 49 50Each of the above tests should be repeated several times and the STD tests 51should be mixed with the STR tests. If any of them fails, the driver cannot be 52regarded as suspend/resume-safe. 53