Power management

  • azzapkp
Posted: Wed, 02/18/2009 - 22:49
I have just tried passing a few options to the kernel in GRUB: acpi=off, pci=noacpi, apm=off. This has saved me about 6 IRQ's and has dropped my soundcard from IRQ 19 down to IRQ 10, which, if I am not mistaken, will give it a higher priority. When shutting down, however, the PC will not switch off. Is there a way to fix this problem, or otherwise is there a way I can disable the shutdown splash screen so I can know when it is safe to power off by using the switch?

All clear

  • azzapkp
  • 02/12/09
  • Sat, 02/21/2009 - 11:54
Hi SKullnotions, thanks for the tips (I'm OK with grep it's a beatutiful tool I use daily). I ran sudo lsusb -v and lspci just to make sure my USB mouse is on a different IRQ; that's the only other thing I could think of that may be a problem should get it a bit wrong somewhere :) ... and now off to find the next thing to tinker with....

Kernel options & usb

  • skullnotions
  • 09/29/07
  • Thu, 02/19/2009 - 13:36
Hi azzapkp, vga=791 makes the verbose smaller, vga=0x31a makes it even smaller again, but only works with certain graphics addapters. Don't worry about the thermal warning, the kernel can't find the module, you could try to "blacklist" it but I don't bother. Once you know key words in /var/log/messages e.g. eth0 hda sda EXT3 usb etc., you can use grep to search for info. grep is a great tool, and can save a lot of reading through files/documents. $ lsusb Will give some info, also Search the forum for usb. $ sudo grep "usb" /var/log/messages $ sudo grep "ehci_hcd" /var/log/messages $ sudo find / -name "*usb" (will search for usb) "may take a minute to search" $ sudo find / -name "*usb" >find-usb (will search for usb and create a file in ~/ called find-usb) $ grep doc find-usb (will search for doc in the find-usb file) The main issue with IRQ sharing is when the Sound card shares with the Graphics Card, this can really influence audio performance. I think your settings are fine. Cheers! dave

acpi=off, pci=noacpi, apm=off

  • skullnotions
  • 09/29/07
  • Thu, 02/19/2009 - 01:25
Hi azzapkp, Removing acpi=off, pci=noacpi, apm=off will do a great job of stopping IRQ's being shared and help with performance. Laptops sometimes do need these options left alone for power management etc., PC's with PCI cards should be fine... "noapic" is another useful option that can be passed to the kernel. The pc shutdown "power off" will not work automatically when you use these options, as you say you will have to power off manually. What options do you have on the kernel line now? remove splash entries or use nosplash I use: acpi=off noapic pci=noacpi vga=791 This gives me the option to read the boot verbose at boot up and shut down. I like to read these messages. Check all is ok using grep "acpi" etc., $ sudo grep "acpi" /var/log/messages Or: Main Menu > Administration > System Log (on 3.0 alpha). Cheers! dave

Kernel options

  • azzapkp
  • 02/12/09
  • Thu, 02/19/2009 - 10:40
@skullnotions : thanks! nosplash leaves the details scrolling so I can see when the system has halted. The options I have now are ro acpi=off pci=noacpi apm=off noapic vga=791 nosplash When I search /var/log/messages, I get the following. Feb 19 23:31:28 64studio kernel: Kernel command line: root=/dev/hdd2 ro acpi=off pci=noacpi apm=off noapic vga=791 nosplash Feb 19 23:31:28 64studio kernel: thermal: Unknown symbol acpi_processor_set_thermal_limit When I chec /proc/interrupts, I see that my soundcard is sharing an IRQ with a USB port: 10: 0 XT-PIC-XT uhci_hcd:usb3, ICE1712 If I avoid using that USB port they will share nicely right? Is there a way of finding out which USB ports are in use without tracing them on the motherboard? Thanks