Guten Morgen,
On Fri, Nov 05, 2004 at 07:42:06PM +0100, Michael Karbach wrote:
Hi!
With SuSE-9.2 I have some trouble with resuming my DELL-C840 from suspend-to-RAM within ACPI. The problem is that the display backlight does not switch on after resume. I can login from remote and shutdown and reboot the system. Everything else seems to work after resume.
lucky you... :-) Suspend to RAM with ACPI actually works only with very few machines.
Suspend-to-disk works, but is really slowly.
later...
Does anybody know how to switch on the backlight?
no, not generic. If you find out how to do it, please tell it the guys on the acpi-devel mailinglist :-) There are some hardware-specific hacks floating around, they all include patching the kernel and some other of them need some userspace tools to reactivate the graphics card. Search the acpi-devel archives, there are many threads about these problems. There is also documentation about things to try in /usr/src/linux/Documentation/power/video.txt (needs kernel-source package installed).
But why is suspend to disk so slow for you? There are some things you can do to speed it up: - remove the useless screenlock at suspend: remove "screen_saver" from POWERSAVE_EVENT_GLOBAL_SUSPEND2DISK in /etc/sysconfig/powersave/events - unload less module before suspend. The USB and firewire modules are only unloaded to prevent users from doing stupid things and complaining about it later (if you do not unload them, you should of course not do stupid things like suspending with an external USB/firewire drive attached). So just remove 'usb_storage sbp2 ohci_hcd uhci_hcd ehci_hcd ohci1394' from POWERSAVE_UNLOAD_MODULES_BEFORE_SUSPEND2DISK in /etc/sysconfig/powersave/sleep. With those two changes, i get reasonably fast suspend to disk (less than half a minute from "powersave -U" until poweroff and ~40 seconds from pressing enter at the GRUB prompt until i can work again).