Created attachment 67802 [details] alsa-info.txt Is there a way to eliminate this problem? The click is very loud, unpleasant and it makes my HiFi speakers tremble.
This sort of problem is very specific to each h/w implementation, so it's hard to debug remotely. Usually this happens at the time of D-state change or EAPD/pin shutdown, and putting some delays() between the transition often fixes the issue. Does the noise appear at suspend or at resume? Also, could you check 3.1-rc1 kernel whether the problem is still present? We can debug easier 3.1-rc kernel.
(In reply to comment #1) > Does the noise appear at suspend or at resume? Also, could you check 3.1-rc1 > kernel whether the problem is still present? We can debug easier 3.1-rc > kernel. I'm not sure if it happens during a suspend/resume cycle, but there's a click even during the time when ALSA modules are being loaded. 3.1-rc1 kernel has the same issue.
The power-saving is a sort of suspend/resume. Judging from your description, the pop noise comes up with the resume phase. The fact that it even appears at the module loading time implies that the very initial power-up sequence already causes the noise. A remaining question is whether you hear a noise at going to power-down. Do you?
(In reply to comment #3) > A remaining question is whether you hear a noise at going to power-down. Do > you? If by power-down you meant an HDA codec power down mode then yes I also hear a noise (power up sequence produces two very loud clicks, and power down sequence produces one less loud click). I'm running 3.1-rc3. Another problem I'd like to report is that Windows installed on the same PC is at least 2-3 times louder than Linux on maximum volume settings (and all intermediate volume settings in Linux are also 2-3 times quieter). I guess this issue needs a different bug report, doesn't it?
This bug was fixed in kernel 3.3 or even earlier, at least I cannot reproduce it any longer (on 3.5.2).