Novell LINUX ENTERPRISE SERVER 10 - INSTALLATION AND ADMINISTRATION 04-08-2006 Installation Manual page 540

3 Copy the file DSDT.aml to any location (/etc/DSDT.aml is recommended).
CPU Frequency Does Not Work
Refer to the kernel sources (kernel-source) to see if your processor is supported.
You may need a special kernel module or module option to activate CPU frequency
control. This information is available in /usr/src/linux/Documentation/
cpu-freq/*. If a special module or module option is needed, configure it in the file
/etc/sysconfig/powersave/cpufreq by means of the variables
CPUFREQD_MODULE and CPUFREQD_MODULE_OPTS.
Suspend and Standby Do Not Work
There are several kernel-related problems that prevent the use of suspend and standby
on ACPI systems:
• Currently, systems with more than 1 GB RAM do not support suspend.
• Currently, multiprocessor systems and systems with a P4 processor (with hyper-
threading) do not support suspend.
The error may also be due to a faulty DSDT implementation (BIOS). If this is the case,
install a new DSDT.
On ACPI and APM systems: When the system tries to unload faulty modules, the system
is arrested or the suspend event is not triggered. The same can also happen if you do
not unload modules or stop services that prevent a successful suspend. In both cases,
try to identify the faulty module that prevented the sleep mode. The log files generated
by the powersave daemon in /var/log/suspend2ram.log and /var/log/
suspend2disk.log are very helpful in this regard. If the computer does not enter
the sleep mode, the cause lies in the last module unloaded. Manipulate the following
settings in /etc/sysconfig/powersave/sleep to unload problematic modules
prior to a suspend or standby.
UNLOAD_MODULES_BEFORE_SUSPEND2DISK=""
UNLOAD_MODULES_BEFORE_SUSPEND2RAM=""
540 Installation and Administration
Edit /etc/sysconfig/kernel and adapt the path to the DSDT file accord-
ingly. Start mkinitrd (package mkinitrd). Whenever you install the kernel
and use mkinitrd to create an initrd, the modified DSDT is integrated and
loaded when the system is booted.