ASoC: soc-link: add mark for snd_soc_link_hw_params/free()
authorKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Tue, 29 Sep 2020 04:31:25 +0000 (13:31 +0900)
committerMark Brown <broonie@kernel.org>
Mon, 26 Oct 2020 16:44:15 +0000 (16:44 +0000)
commit918ad772c4e47f26bc1b5040a79336b7063626cf
treecd3e32009a6c75a6e40d09eceb19b030dc741e84
parentab49436eecf5cc779a1ff659ba59c88779685b47
ASoC: soc-link: add mark for snd_soc_link_hw_params/free()

soc_pcm_hw_params() does rollback when failed (A),
but, it is almost same as soc_pcm_hw_free().

static int soc_pcm_hw_params(xxx)
{
...
if (ret < 0)
goto xxx_err;
...
return ret;

 ^ component_err:
 | ...
 | interface_err:
(A) ...
 | codec_err:
 | ...
 v return ret;
}

The difference is
soc_pcm_hw_free() is for all dai/component/substream,
rollback          is for succeeded part only.

This kind of duplicated code can be a hotbed of bugs,
thus, we want to share soc_pcm_hw_free() and rollback.

Now, soc_pcm_hw_params/free() are handling
=> 1) snd_soc_link_hw_params/free()
2) snd_soc_pcm_component_hw_params/free()
3) snd_soc_dai_hw_params/free()

This patch is for 1) snd_soc_link_hw_params/free().

The idea of having bit-flag or counter is not enough for this purpose.
For example if one DAI is used for 2xPlaybacks for some reasons,
and if 1st Playback was succeeded but 2nd Playback was failed,
2nd Playback rollback doesn't need to call shutdown.
But it has succeeded bit-flag or counter via 1st Playback,
thus, 2nd Playback rollback will call unneeded shutdown.
And 1st Playback's necessary shutdown will not be called,
because bit-flag or counter was cleared by wrong 2nd Playback rollback.

To avoid such case, this patch marks substream pointer when hw_params() was
succeeded. If rollback needed, it will check rollback flag and marked
substream pointer.

One note here ist that it cares *previous* hw_params() only now,
but we might want to check *whole* marked substream in the future.
This patch is using macro named "push/pop", so that it can be easily
update.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87lfgtgqba.wl-kuninori.morimoto.gx@renesas.com
Signed-off-by: Mark Brown <broonie@kernel.org>
include/sound/soc-link.h
include/sound/soc.h
sound/soc/soc-link.c
sound/soc/soc-pcm.c