57 lines
2 KiB
Plaintext
57 lines
2 KiB
Plaintext
![]() |
How to get s2ram working
|
||
|
~~~~~~~~~~~~~~~~~~~~~~~~
|
||
|
2006 Linus Torvalds
|
||
|
2006 Pavel Machek
|
||
|
|
||
|
1) Check suspend.sf.net, program s2ram there has long whitelist of
|
||
|
"known ok" machines, along with tricks to use on each one.
|
||
|
|
||
|
2) If that does not help, try reading tricks.txt and
|
||
|
video.txt. Perhaps problem is as simple as broken module, and
|
||
|
simple module unload can fix it.
|
||
|
|
||
|
3) You can use Linus' TRACE_RESUME infrastructure, described below.
|
||
|
|
||
|
Using TRACE_RESUME
|
||
|
~~~~~~~~~~~~~~~~~~
|
||
|
|
||
|
I've been working at making the machines I have able to STR, and almost
|
||
|
always it's a driver that is buggy. Thank God for the suspend/resume
|
||
|
debugging - the thing that Chuck tried to disable. That's often the _only_
|
||
|
way to debug these things, and it's actually pretty powerful (but
|
||
|
time-consuming - having to insert TRACE_RESUME() markers into the device
|
||
|
driver that doesn't resume and recompile and reboot).
|
||
|
|
||
|
Anyway, the way to debug this for people who are interested (have a
|
||
|
machine that doesn't boot) is:
|
||
|
|
||
|
- enable PM_DEBUG, and PM_TRACE
|
||
|
|
||
|
- use a script like this:
|
||
|
|
||
|
#!/bin/sh
|
||
|
sync
|
||
|
echo 1 > /sys/power/pm_trace
|
||
|
echo mem > /sys/power/state
|
||
|
|
||
|
to suspend
|
||
|
|
||
|
- if it doesn't come back up (which is usually the problem), reboot by
|
||
|
holding the power button down, and look at the dmesg output for things
|
||
|
like
|
||
|
|
||
|
Magic number: 4:156:725
|
||
|
hash matches drivers/base/power/resume.c:28
|
||
|
hash matches device 0000:01:00.0
|
||
|
|
||
|
which means that the last trace event was just before trying to resume
|
||
|
device 0000:01:00.0. Then figure out what driver is controlling that
|
||
|
device (lspci and /sys/devices/pci* is your friend), and see if you can
|
||
|
fix it, disable it, or trace into its resume function.
|
||
|
|
||
|
For example, the above happens to be the VGA device on my EVO, which I
|
||
|
used to run with "radeonfb" (it's an ATI Radeon mobility). It turns out
|
||
|
that "radeonfb" simply cannot resume that device - it tries to set the
|
||
|
PLL's, and it just _hangs_. Using the regular VGA console and letting X
|
||
|
resume it instead works fine.
|