On Mon, 2008-07-14 at 09:51 +0200, Valent Turkovic wrote: > So as per your blog post this is bug over a year old. Is my bug a > duplicate of it in bugzilla? If so please post the link. In fedora bugzilla I've not checked -- but there's a few in the kernel bugzilla and the alsa bugtracker. > Is there something that we users who aren't developers can do so that > this bug gets fixed faster? Is there some log, some debug output that > would help kernel developers to find how to deal with these sound > chips? Well, to be honest, I'm not sure how to go forward. Using WindowsXP, you don't get the sounds clicks, so either the windows driver has worked out a way of powering up the soundcard without a DC click, or the windows driver just doesn't power down the soundcard. You can be sure there's some vendor whitelist/blacklist trickery going on. We also think this is probably a per-laptop thing, rather than a per-chipset thing, so a kernel blacklist would be pretty hard to populate. The alsa docs explain things a bit better: """ With the automatic power-saving, the driver turns off the codec power appropriately when no operation is required. When no applications use the device and/or no analog loopback is set, the power disablement is done fully or partially. It'll save a certain power consumption, thus good for laptops (even for desktops). The time-out for automatic power-off can be specified via power_save module option of snd-ac97-codec and snd-hda-intel modules. Specify the time-out value in seconds. 0 means to disable the automatic power-saving. The default value of timeout is given via CONFIG_SND_AC97_POWER_SAVE_DEFAULT and CONFIG_SND_HDA_POWER_SAVE_DEFAULT Kconfig options. Setting this to 1 (the minimum value) isn't recommended because many applications try to reopen the device frequently. 10 would be a good choice for normal operations. The power_save option is exported as writable. This means you can adjust the value via sysfs on the fly. For example, to turn on the automatic power-save mode with 10 seconds, write to /sys/modules/snd_ac97_codec/parameters/power_save (usually as root): # echo 10 > /sys/modules/snd_ac97_codec/parameters/power_save Note that you might hear click noise/pop when changing the power state. Also, it often takes certain time to wake up from the power-down to the active state. These are often hardly to fix, so don't report extra bug reports unless you have a fix patch ;-) For HD-audio interface, there is another module option, power_save_controller. This enables/disables the power-save mode of the controller side. Setting this on may reduce a bit more power consumption, but might result in longer wake-up time and click noise. Try to turn it off when you experience such a thing too often. """ Richard. -- fedora-devel-list mailing list fedora-devel-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/fedora-devel-list
