From a122a116fc6d8fcf2f202dcd185173a54268f239 Mon Sep 17 00:00:00 2001

From: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>

Date: Thu, 8 Apr 2021 13:28:38 +0900

Subject: [PATCH] ASoC: rsnd: call rsnd_ssi_master_clk_start() from rsnd_ssi_init()

Git-commit: a122a116fc6d8fcf2f202dcd185173a54268f239

Patch-mainline: v5.13-rc1

References: git-fixes

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 4d230d1271064 ("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 06e8f5c842f2d ("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>

Acked-by: Takashi Iwai <tiwai@suse.de>

---

 sound/soc/sh/rcar/ssi.c | 14 +++++---------

 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/sound/soc/sh/rcar/ssi.c b/sound/soc/sh/rcar/ssi.c

index d071cec25f71..048d53566127 100644

--- a/sound/soc/sh/rcar/ssi.c

+++ b/sound/soc/sh/rcar/ssi.c

@@ -506,10 +506,15 @@ static int rsnd_ssi_init(struct rsnd_mod *mod,

 			 struct rsnd_priv *priv)

 {

 	struct rsnd_ssi *ssi = rsnd_mod_to_ssi(mod);

+	int ret;

 	if (!rsnd_ssi_is_run_mods(mod, io))

 		return 0;

+	ret = rsnd_ssi_master_clk_start(mod, io);

+	if (ret < 0)

+		return ret;

+

 	ssi->usrcnt++;

 	rsnd_mod_power_on(mod);

@@ -1060,13 +1065,6 @@ static int rsnd_ssi_pio_pointer(struct rsnd_mod *mod,

 	return 0;

 }

-static int rsnd_ssi_prepare(struct rsnd_mod *mod,

-			    struct rsnd_dai_stream *io,

-			    struct rsnd_priv *priv)

-{

-	return rsnd_ssi_master_clk_start(mod, io);

-}

-

 static struct rsnd_mod_ops rsnd_ssi_pio_ops = {

 	.name		= SSI_NAME,

 	.probe		= rsnd_ssi_common_probe,

@@ -1079,7 +1077,6 @@ static struct rsnd_mod_ops rsnd_ssi_pio_ops = {

 	.pointer	= rsnd_ssi_pio_pointer,

 	.pcm_new	= rsnd_ssi_pcm_new,

 	.hw_params	= rsnd_ssi_hw_params,

-	.prepare	= rsnd_ssi_prepare,

 	.get_status	= rsnd_ssi_get_status,

 };

@@ -1166,7 +1163,6 @@ static struct rsnd_mod_ops rsnd_ssi_dma_ops = {

 	.pcm_new	= rsnd_ssi_pcm_new,

 	.fallback	= rsnd_ssi_fallback,

 	.hw_params	= rsnd_ssi_hw_params,

-	.prepare	= rsnd_ssi_prepare,

 	.get_status	= rsnd_ssi_get_status,

 };

-- 

2.26.2