Re: Re: No snd_pcm_resume_all() ?

[Takashi Iwai <tiwai@suse.de>]

At Tue, 18 Apr 2006 20:40:53 +0200,
Johannes Berg wrote:
> 
> On Tue, 2006-04-18 at 20:25 +0200, Takashi Iwai wrote:
> 
> > Yes, of course, it's not an XRUN but "another type" of state.
> > The driver just notifes the SUSPENDED state when any access comes from
> > the app.
> 
> I still don't see why it is necessary. I can see two cases:
> 
> 1) the app is frozen before the driver suspends, so that we get into a
> regular xrun situation. That can be handled as an xrun
> 
> 2) the driver suspends before the app is frozen, which means that the
> app won't be getting any pcm progress for a bit of time, which doesn't
> matter at all. Or is that the point where I'm mistaken, and it does
> matter to the app if the hardware pauses for a bit (say for video/audio
> sync)?

Another reason is that not all drivers provide the full resume
capability.  Most drivers provide only the partial suspend -- the
driver can restore the hardware setting but the PCM must be restarted
for a proper operation.  In this case, the app requires the explicit
reset-and-restart.  So, it matter for apps what the current status
is.

IIRC, I discussed it for using a XRUN instead of an individual
SUSPENDED state in order to simplify the system, but it was rejected
by reasons I forgot :)


Takashi


-------------------------------------------------------
This SF.Net email is sponsored by xPML, a groundbreaking scripting language
that extends applications into web and mobile media. Attend the live webcast
and join the prime developer group breaking into this new coding territory!
http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642