[alsa-devel] [PATCH 1/1] ASoC: TWL4030: Wait RAMP_DELAY on headsetl_event: POST_PMD

Peter Ujfalusi peter.ujfalusi at nokia.com
Tue May 12 15:16:08 CEST 2009

On Tuesday 12 May 2009 15:21:55 ext Jarkko Nikula wrote:
> On Tue, 12 May 2009 15:16:40 +0300
> Peter Ujfalusi <peter.ujfalusi at nokia.com> wrote:
> > > Looks like the beep is caused by the ramp operation since beep is
> > > gone in power-down when reverting both of your patches but it's
> > > still present in power-up.
> >
> > But the 'tuck' still there after you have reverted the patches?
> Yep it was there even it sounds bit more silent when going to longer
> ramp times. Beep was present only with '109/81/55 ms'.

Now I'm even more confused...
Without the patches that you have reverted, the ramp delay does not matter 
after the playback. It just cuts the VMID and that's it.
On startup the ramp is initiated. If you set the ramp delay longer, than it is 
possible that the beginning of the audio is played already when the VMID is 
ramping up.

So with the ramp (down) delay - the patches that you have reverted - the 
'tuck' was worst after playback, than without the proper ramp (down) delay 

I can see on the scope, that the ramp up also has kind of 'tuck' problem, but 
it comes when the VMID is quite low, so it is harder to hear it. By making the 
ramp delay longer, this 'tuck' happens when the VMID is close to 0, so it 
makes it less audible.


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