On Sat, Feb 06, 2010 at 07:33:08PM +0200, Grazvydas Ignotas wrote:
On Fri, Feb 5, 2010 at 7:20 PM, Mark Brown
Which step of the powerup is the one that generates the pop? As Liam says if you can mute the DAC while powering up might help if that's possible, though looking I don't think it is.
It's on powerdown, there is a faint pop. It appears its the amp (final part in the path), I tried to toggle it while playing /dev/zero manually and it always pops on powerdown. On powerup there is a small
Like Jarkko says be careful what you're actually playing there - especially given the ramp you appear to have at startup which would mask any sudden DC offset in the samples at startup.
sound cutoff too, probably because of amp capacitors charging, but we decided to leave it instead of halting every sound playing program until the amp gets ready.
If this goes off too much you might want to tweak the delay ASoC uses to defer power down of DAPM widgets after streams stop. There's a command line option pmdown_time, it really ought to have a sysfs file to tweak but there's not been any demand.