ASoC: rsnd: call rsnd_ssi_master_clk_start() from rsnd_ssi_init()

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Current rsnd needs to call .prepare (P) for clock settings,
.trigger for playback start (S) and stop (E).
It should be called as below from SSI point of view.

	P -> S -> E -> P -> S -> E -> ...

But, if you used MIXer, below case might happen

	              (2)
	1: P -> S ---> E -> ...
	2:         P ----> S -> ...
	          (1)     (3)

P(1) setups clock, but E(2) resets it. and starts playback (3).
In such case, it will reports "SSI parent/child should use same rate".

rsnd_ssi_master_clk_start() which is the main function at (P)
was called from rsnd_ssi_init() (= S) before,
but was moved by below patch to rsnd_soc_dai_prepare() (= P) to avoid
using clk_get_rate() which shouldn't be used under atomic context.

	commit 4d230d1271 ("ASoC: rsnd: fixup not to call clk_get/set
				under non-atomic")

Because of above patch, rsnd_ssi_master_clk_start() is now called at (P)
which is for non atomic context. But (P) is assuming that spin lock is
*not* used.
One issue now is rsnd_ssi_master_clk_start() is checking ssi->xxx
which should be protected by spin lock.

After above patch, adg.c had below patch for other reasons.

	commit 06e8f5c842 ("ASoC: rsnd: don't call clk_get_rate()
				under atomic context")

clk_get_rate() is used at probe() timing by this patch.
In other words, rsnd_ssi_master_clk_start() is no longer using
clk_get_rate() any more.

This means we can call it from rsnd_ssi_init() (= S) again which is
protected by spin lock.
This patch re-move it to under spin lock, and solves
1. checking ssi->xxx without spin lock issue.
2. clk setting / device start / device stop race condition.

Reported-by: Linh Phung T. Y. <linh.phung.jy@renesas.com>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/875z0x1jt5.wl-kuninori.morimoto.gx@renesas.com
Signed-off-by: Mark Brown <broonie@kernel.org>

...

This commit is contained in:

Kuninori Morimoto 2021-04-08 13:28:38 +09:00 • committed by Mark Brown

parent cdf20c3ef0

commit a122a116fc

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sound/soc/sh/rcar/ssi.c

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