From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040225 Firefox/0.8 Description of problem: When I boot into a recent kernel (2.6.4-1.275 through 2.6.4-1.279, so far), my sound card goes silent (no matter how I adjust the volume). Version-Release number of selected component (if applicable): kernel-2.6.4-1.275 How reproducible: Always Steps to Reproduce: 1. Boot and log in (graphically) as a normal user. 2. Run system-config-soundcard. 3. Enter root password. 4. Click "Play test sound". Actual Results: No sound. (This happens with 2.6.4-1.275 and 2.6.4-1.279.) Expected Results: User hears test sound. (This happens with 2.6.4-1.270 and earlier, includng 2.6.3-2.1.253.2.1.) Additional info: The machine is a Toshiba Portege 3500. This is with the internal speaker; I have not yet tried plugging in external speakers (i.e. I know that works with older kernels but I don't know if the new kernels work with external speakers, or just not at all).
Run alsamixer and unmute 'Master'.
No, master seems to be already unmuted by the time I finish logging in and run alsamixer. Even with it unmuted (and turned up to 75 or so) and with PCM turned up similarly, no sound. With the same setup on older kernels, I get sound. (Unmuting and turning up "Master Mono" doesn't help either.) As I said above, this happens with some kernels and not others. I'm running ALSA in both cases. My current theory (I'm compiling kernels now in order to test it) is that this is a bug that was introduced in 2.6.4-bk4...
Indeed, the problem happens with 2.6.4-bk4, but not 2.6.4-bk3.
2.6.4-bk3 plus this patch also has the problem: ftp://ftp.alsa-project.org/pub/kernel-patches/alsa-bk-2004-03-14.patch.gz
It looks like have to unmute "External" ("External Amplifier") in alsamixer in order to get sound with recent kernels. Even if "Master" and "PCM" are not muted, those alone are insufficient to get sound. BTW, this "External Amplifier" does not appear in aumix (which is an OSS mixer control AFAIK). Right now I don't know if this counts as a userspace bug, a kernel bug, or just problem-exists-between-keyboard-and-chair. However, at a minimum I would expect system-config-soundcard to make sure this is unmuted before playing the test sound (otherwise there is *no way* for the user to hear the sound).
Yeah, alsamixer and gnome-alsamixer will show all the controls. gnome-volume-control in GNOME 2.6 should have support for ALSA controls too. This is a userspace issue, we need to know *all* of the controls that must be unmuted and asoundrc should reflect that. Someone should ask the ALSA devs...
Actually, I think some of them need to stay muted or else you can have *other* sound problems. (I'll post another comment to this bug within the next day or so to explain what I mean by this. Right now I need to get some sleep though.)
Oops, never mind my previous comment, I was tired and misread your (Sahil's) comment. Sorry about that.
Since it's been a while, let me update things: The laptop is question is currently running RHEL 3WS, as I'm looking at it for possible deployment in my day job. Under that distribution, I have not had this sound problem with the recent kernels from <http://people.redhat.com/arjanv/2.6/>. I now need to retest with FC2t3. I'll do that this week, maybe even today.
A fresh install of FC devel (as of 2004-05-05) does not reproduce this bug, so whatever it was, it seems to be fixed now. Closing.