2007-05-08 15:24:07 +08:00
|
|
|
Testing suspend and resume support in device drivers
|
|
|
|
|
(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 the suspend
|
|
|
|
|
to disk (STD) and the suspend to RAM (STR) transitions, because each of these
|
|
|
|
|
cases involves different ordering of 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
|
2007-10-17 14:30:18 +08:00
|
|
|
testing the new driver. Please see Documentation/power/basic-pm-debugging.txt
|
|
|
|
|
for more information about the debugging of suspend/resume functionality.
|
2007-05-08 15:24:07 +08:00
|
|
|
|
|
|
|
|
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 STD in the test mode (see:
|
|
|
|
|
Documents/power/basic-pm-debugging.txt, 1a)).
|
|
|
|
|
|
|
|
|
|
b) Load the driver and attempt to suspend to disk in the "reboot", "shutdown"
|
|
|
|
|
and "platform" modes (see: Documents/power/basic-pm-debugging.txt, 1).
|
|
|
|
|
|
|
|
|
|
c) Compile the driver directly into the kernel and try the STD in the test mode.
|
|
|
|
|
|
|
|
|
|
d) Attempt to suspend to disk with the driver compiled directly into the kernel
|
|
|
|
|
in the "reboot", "shutdown" and "platform" modes.
|
|
|
|
|
|
|
|
|
|
e) Attempt to suspend to RAM using the s2ram tool with the driver loaded (see:
|
|
|
|
|
Documents/power/basic-pm-debugging.txt, 2). As far as the STR tests are
|
|
|
|
|
concerned, it should not matter whether or not the driver is built as a module.
|
|
|
|
|
|
|
|
|
|
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.
|
