Re: dmix, pause, and snd_pcm_delay

[Takashi Iwai <tiwai@suse.de>]

At Tue, 06 Jul 2004 00:46:50 -0700,
Ryan Gammon wrote:
> 
> I've tried to implement this in a couple of different ways:
> 1. Using mmaped timestamps, and converting the time interval between now 
> and when playback triggered into bytes.
> 2. Using bytes_written - snd_pcm_delay()
> 3. Using bytes_written - (initial snd_pcm_avail_update() value - current 
> snd_pcm_avail_update() value
> 4. Using the snd_timer api (still figuring this out)
> 5. Something with snd_pcm_sync_id_t (not sure what this is, or how to 
> use it)

(2) should be the proper way to work.

> 2. This works well until I try to pause. dmix claims support for 
> hardware pause, but when I pause, the hw.ptr seems to keep marching on, 
> and when I unpause, snd_pcm_delay() returns a negative value, as the 
> hardware pointer has become greater than the software pointer.

Ok, it's a bug.
A workaround is to disable pause/resume as your patch.
I'll apply it cvs.

A better fix would be the proper implementation, though...


Takashi


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