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

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>

diff --git a/sound/soc/sh/rcar/ssi.c b/sound/soc/sh/rcar/ssi.c
index d071cec..048d535 100644 (file)
--- 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,
 };