etc/modprobe.conf and modprobe.d confusion via MCC

[eric71]

One very small issue I've encountered with Beta 3 installed from the KDE livecd. I have an oldish Thinkpad Z60m laptop, and also use an usb mixer/sound interface for audio recording. One reason I have loved the MCC so much is the ability to enter module parameters via gui with the hardware section of MCC. It saves having to edit modprobe.conf as root and knowing exactly how to type what is needed. I used this with Mageia 1 to set the USB device to index -2 so that the internal laptop sound card is always default. This didn't seem to work in Mageia 2 beta3 - a different device seemed to be chosen at ramdom. Sometimes the laptop device and sometimes the USB device would be the first audio device. I finally looked at etc/modprobe.conf - and it had indeed been ammended with "options snd_usb_audio index=-2", but in general was a much sparser file with less entries than I remember. It was then I noticed that there is also a modprobe.d folder in /etc which contains a "00_modprobe.conf" file. Amending the "options snd_usb_audio index=-2" line to this file has fixed the problem.

So in short it seems that when configuring driver options in the "Browse and configure hardware" section of Mageia Control Center, changes are being written to etc/modprobe.conf which is apparently not the correct file anymore. Seems it should be etc/modprobe.d/00_modprobe.conf.

[doktor5000]

Normally these days you should not use the MCC to change the index, but use e.g. the means of your desktop environment to control pulseaudiod behaviour, or maybe use something like pavucontrol directly to select primary and secondary device. But for the problem you reported, you should create a bug report so this won't get lost:
https://wiki.mageia.org/en/How_to_report_a_bug_properly

[jaywalker]

If your aged Thinkpad is faster/better endowed in the memory department than my almost ancient T21 then you might well be using Pulse Audio. I cannot afford the extravagance on my laptop so I keep it Pulse-free. Thank you for the heads up on what not to rely on for changing sound module parameters.

My normal practice is to put individual hardware-specific .conf files in /etc/modprobe.d, but I have often looked at the module configuration screen in mcc's hardware page and wondered why it doesn't list the current module parameters for editing.

[doktor5000]

Actually this is only a cauldron problem. Otherwise i don't know what extravgance you're talking about related to pulse, but whatever ...

[jaywalker]

It doesn't manage sound very efficiently on a PIII 900. You will doubtless appreciate that this class of machine has little processing power to spare on an extra layer between the user and the sound card.

[wilcal]

....I have an oldish Thinkpad Z60m laptop......

You should try:

http://www.puppylinux.com/

Puppy is much better suited for that machine. I've had great success
to recommend Puppy for lots of folks running that Class of Laptop.
Puppy actually runs faster then the original Windows 98/XP that
was installed on them.

[eric71]

I never use pulse - another reason I like Mageia. It's easy to disable with one click in MCC, and KDE adapts much easier to this than Gnome. I'm recording via jackd and a program running with Wine. When using pulse, I just get more xruns (basically recording dropouts). Adding an extra sound server in there just bumps up the latency another little bit. For everyday use, I'm sure pulse is fine. As I don't use it, I had expected to be able to select the correct card in the KDE control center, but the internal card was selected in KDE and that didn't make a difference. I'm happy with my fix, but I have to admit I haven't had the time until now to file the bug. I will do so.

As an aside, I'm really happy with how Mageia 2 beta3 is running. I'm getting really great performance with the TMB desktop kernel and my recording setup. Way better than Kubuntu with their lowlatency kernel. And the rate of updates at this late stage of development shows me just how active and comitted the developers of this distro are, and how good it will be when it goes final.