Yesterday I migrated to the Linux kernel 2.6.0. I wanted to relate some of the hiccups that I faced in doing so.<\/p>\n
I was motivated initially by the fact that my audio drivers skip regularly. I have a cheap C-Media soundcard, and the OSS drivers for it apparently suck. Moreover, I suddenly found that I had a use for the fact that the card has a rear-output jack. I built a small FM radio transmitter<\/a> recently, and I’d like to be able to adjust the output (and output volume) for the transmitter separately from the regular speakers. Fortunately, the ALSA driver for this card <\/a> doesn’t skip, and can handle the rear output somewhat. Unfortunately, at this time, it doesn’t do everything I want; I can play seperate audio on the rear output, with no volume control, or I can play the same audio on both front and rear with the volume the same, but I can’t play the same signal on both channels with independent volume.<\/p>\n So, I could have switched to ALSA without swtiching to 2.6.0, but the fact that ALSA is a stock feature of 2.6 was a motivating factor to switch, and get all the scheduler and IO improvements also.<\/p>\n Here were the issues I faced with the migration to Linux 2.6.0:<\/p>\n I’d used ALSA before, but I always found it to be a pain in the butt, partly because it’s more complicated than OSS, but largely because it’s a pain to have to update external drivers everytime I update the kernel, and ALSA drivers have historically tracked the kernel closely; requiring new downloads for each kernel. Now that ALSA is included in the kernel, this is a non-issue.<\/p>\n But I still wanted XMMS<\/a> to work, including the volume control. It was easy enough with Debian to install the ALSA version of ESD, but the volume control still didn’t work. After some gnashing of teeth, I determined that loading the snd_mixer_oss<\/tt> kernel module did the trick.<\/p>\n As noted above, I’ve done some wrestling with ALSA mixers and the CMIPCI driver already. It does some of what I want, but not eveything. Sigh. I can accept it, or fix it. <\/p>\n I needed to get fresh HostAP drivers which is one of the few things that I needed that isn’t included in the kernel by default. This turned out to be almost painless. Historically HostAP hasn’t needed to be updated; when I went through the 2.4 series kernel, I just needed to recompile HostAP, but the code was the same. Well, the 2.4 HostAP code doesn’t work with kernel 2.6, but it was still pretty painless to go get it.<\/p>\n<\/p>\n