On 2022-11-14 2:02 PM, Takashi Iwai wrote:
On Mon, 14 Nov 2022 12:37:29 +0100,
Cezary Rojewski wrote:
To improve performance and overall system stability, suspend/resume
operations for ASoC cards always return success status and defer the
actual work.
Because of that, if a substream fails to resume, userspace may still
attempt to invoke commands on it as from their perspective the operation
completed successfully. Set substream's state to DISCONNECTED to ensure
no further commands are attempted.
...
Hm, that might work, but note that, once when the stream is set with
the disconnected state, it won't be taken back to the normal state any
longer on most sound backends. That is, it'll be gone and won't
revive unless you completely unload and reload the whole stuff. If
that's the intended behavior, that's fine, of course. So just to make
sure.
Good point.
Our intention: if we fail e.g.: on resume, we would like the framework
to invoke ->hw_free() and close us. Right now, if we pretend that
everything is okay, invalid actions can be performed on our streams.
This all comes down to userspace calling "just" snd_pcm_resume(). If we
had an option to opt-in to a _hw_params() + _prepare() + _resume() path,
then things would look differently.
