Re: [PATCH] cs46xx update SMP fixes

[Takashi Iwai <tiwai@suse.de>]

At Thu, 22 Aug 2002 15:33:05 +0200,
Benny Sjostrand wrote:
> 
> >
> >
> >could you rewrite mutex with spinlock if not too long held?
> >
> >you cannot use mutex on trigger since this could be called from
> >interrupt handlers, too (in order to stop the stream when xrun is
> >detected).
> >
> I believe that the critical sections are too long and will lose to much 
> performance
> on a SMP machines that's why i've choose the mutex instead of spin_locks.
> However, that the trigger functions could be called from interrupt 
> context is new to me,
> thanks to pointing it out.
> Mutexes are used in _trigger function in current CVS too, not directly 
> in trigger function,
> but in _link and _unlink function called by _trigger, and SMP is broken, 
> so in  some
> way we need to fix it.
> 
> I'll try to come with another solution, if you have any suggestion how 
> to solve it, then great.

how about to do pcm_link/unlink in open/close or prepare callback?
they are definitely not called from interrupts.


Takashi


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