On the other side of cloud

Tags:KDE linux multimedia thinkpad

I supposed that my T40’s built-in microphone was ruined(for this is a second-hand thinkpad). But accidentally, I found it works well…
And here are some tips for laptop’s built-in microphone on KDE(KMix):
1. You can test if you microphone works by click the green point below the mic icon(Input tab) to make it light and connect the input of microphone to speaker, then flap your Mic. But be careful, if you use built-in speaker, the treble voice would be generated if you adjust the volume to more than level 3. So, in the normal use, please close the microphone output to speaker(except you use headphone).
2. You can enhanced the microphone output. Click Switches tab in KMix, and select Mic Boost +20dE. But don’t make microphone connect to built-in speaker with this.
3. If you still not content with the result, you can set the Capture of Input tab to maximum.
4. You can also use vumeter -r to see the recode volume level.

I got very perfect result with disable Mic to output, using Mic Boost and using built-in speaker.
Good luck!

Tags:acpi linux thinkpad

It’s should be simple to get special key of thinkpad like Fn-F3 work on debian, and if you don’t know, you can see here.

I am using ibm-acpi, and everything goes well, except Fn+F3. I found there is a bug on debian package result in Fn+F3(close lcd) failed. The /etc/acpi/screenblank.sh which was called by ibm-acpi called getXuser from /usr/share/acpi-support/powerfunc, and this script assumed that you boot with gdm/kdm/xdm, so it using something like:

user=`finger| grep -m1 “:$displaynum “ | awk ‘{print $1}’`

to find your current user name. But if you boot from init 2 as me, that’s failed. Finger won’t show “:0″ or some other thing on your line, so getXuser will fail.

I fix this issue with add these lines in getXuser function:

if [ x“$user” = x“” ]; then
user=`finger| grep -m1 “*tty” | awk ‘{print $1}’`
fi

Though it not very precise, it works.

Tags:kernel linux madwifi module

After upgrading to madwifi svn (now released 0.9.3), I found I encountered maybe a seldom problem: the linux kernel module loading order.

In the latest madwifi, it provides three different rate control algorithms, ONOE, AMRR and SAMPLE, instead of only SAMPLE in the previous version. Though SAMPLE is the most advanced one and is used by default, the other two must have ability to take over it’s job. So modules dependency relationship can’t be hardcode into source. But when you insert these modules to /etc/modules for kernel loading when booting, the kernel will take ath_pci first, which depends on ath_rate_sample or other rate control modules. So, the ath_pci can’t be loaded completely success but was still loaded, and reports:

Unable to load needed module: ath_rate_sample; no support for automatic module loading<3>Error loading module “ath_rate_sample”

Then, if you still want to use it, you must reload ath_pci manually, for ath_rate_sample is loaded after ath_pci, but the former didn’t know it, and it can’t specify ath_rate_sample as its depend modules for this can be specify when it was loading.

UPDATE: Thank Matt tell me the real reason: The “automatic module loading” wasn’t open when we compiling the kernel (and in fact error message tell me of that clearly…).
So, please recompile your kernel with “automatic modules loading”(CONFIG_KMOD=y), and recompile your madwifi modules with your new kernel. Then try to load it normally. It’s more useful…
It seems silly to try to load these modules manually… I’m sorry…

SO PLEASE FORGET THE THING BELOW EXCEPT YOU REALLY ENCOUNTER SOME UGLY MODULES…

The only method to solve this is to specify the kernel modules loading order, but the loading order seems can’t be specify simply by /etc/modules (I checked module-init-tools, but don’t understand why it don’t load the modules by order — it meant to do it…). So I add a script in /etc/init.d/ to do this, and link it to /etc/rcS.d/S21load-madwifi.sh(just after module-init-tools)

1 #!/bin/bash
2 #load-madwifi.sh
3
4 modprobe -r ath_pci
5 modprobe -r wlan_tkip
6 modprobe -r wlan_scan_sta
7 modprobe -r ath_rate_sample
8
9 modprobe ath_rate_sample
10 modprobe wlan_scan_sta
11 modprobe wlan_tkip
12 modprobe ath_pci

If you are a debian user, you can simply use:

sudo modconf –load-before ath_rate_sample –load-before \
wlan_scan_sta –load-before wlan_tkip –load-only ath_pci

That’s it.

Tags:kernel linux pae xen

I am trying to install xen on my debian a week ago, but failed because of that damn PAE build-in debian kernel for xen and my poor Pentium-M without PAE. Today I retried to install xen(now the version is 3.0.4) from source. Follow the README in the package, everything goes well except extremely long time waiting for kernel compiling - it filled kernel with all kinds of driver modules…

I went with option KERNELS=”linux-2.6-xen0 linux-2.6-xenU” first, everything goes well. But when I try to customize kernel and build a linux-2.6-xen kernel(not only a dom0, but also a an unprivileged guest kernel), and reboot it, I found I encountered this:

VFS: Cannot open root device “hda7″ or unknown-block(0,0)
Please append a correct “root=” boot option
Kernel panic - not syncing: VFS: Unable to mount root fs on
unknown-block(0,0) (XEN) Domain 0 crashed: rebooting machine in 5
seconds. (XEN) Domain 0 crashed: rebooting machine in 5 seconds.

I double checked my /boot/grub/menu.lst, and it was written correctly. So I looked it for google, and mailing list of xen-users told me that:

The -xen kernel is built with almost all drivers configured as modules; hence you’ll need an initrd including the driver[s] for your scsi or ide controller so you can mount the root filesystem.

So what I have to do is add a initrd for my xen kernel. But later I found that mkinitrd which mentioned in README is out of date. According to the Debian Wiki, debian have switched from initrd to initramfs. So another tool is introduced. Offical debian kernel package needs initramfs to preload modules that the kernel didn’t build in but as a module(e.g. ext3, ide, input device), just like the case linux-2.6-xen.

It’s easy to get a initramfs with yaird(and also mkinitramfs can be used too, which appears to be more widely used). Yaird’s configure file located at /etc/yarid, but almost nothing need modified in my case. So I only run following command as a sudoer:

yaird –verbose –output=/boot/initrd.img-xen 2.6.16.33-xen

And appended the following line to the xen’s section in /boot/grub/menu.lst:

title Xen 3.0.4 / XenLinux 2.6.16.33
root (hd0,6)
kernel /boot/xen-3.0.gz
module /boot/vmlinuz-2.6.16-xen root=/dev/hda7 ro console=tty0
module /boot/initrd.img-xen

Take care of “module”. It isn’t “initrd”, for xen take over the kernel while booting.

And reboot, everything goes well with your customize kernel.