>> I think the only solution is to follow the example of the PCM case, >> where the type of lock depends on the FE types, with the assumption that >> there are no mixed atomic/non-atomic FE configurations. > > Yes, and I guess we can simply replace those all card->dpcm_lock with > FE's stream lock. It'll solve the atomicity problem, too, and the FE > stream lock can be applied outside the loop of dpcm_be_disconnect() > gracefully. > > And, this should solve the race with dpcm_be_dai_trigger() as well, > because it's called from dpcm_fe_dai_trigger() that is called already > inside the FE's stream lock held by PCM core. A PoC is something like > below. (I replaced the superfluous *_irqsave with *_irq there) No I don't think so. The code starts from an FE and loops for all the BEs connected to that FE, but we want to serialize at the BE level! we really need a dpcm lock at the card level, not the FE/stream level. I am testing a quick set of changes at https://github.com/thesofproject/linux/pull/3201, where I also replaced irqsave by irq btw.
