Re: [alsa-devel] [RFC PATCH] ALSA: core: Add DMA share buffer support

On Fri, 25 Jan 2019 at 21:04, Takashi Iwai tiwai@suse.de wrote:

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Erm, obviously it's not enough. Each attach / detach needs to manage the refcount, too, for covering the cases above. It can re-use the PCM mmap_refount, though.

But we've used the DMA buffer file's refcounting to manage the DMA buffer. So is this not enough?

Unless you manage the PCM substream refcount (or block the state change), the PCM stream itself can be released (or re-setup) freely.

OK. Thanks for your comments.