[PATCH] ASoC: rsnd: check rsnd_adg_clk_enable() return value

[Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>]

rsnd_adg_clk_enable() might be failed for some reasons, but it doesn't
check return value for now. In such case, we might get below WARNING from
clk_disable() during probe or suspend. Check rsnd_adg_clk_enable() return
value.

    clk_multiplier already disabled
    ...
    Call trace:
     clk_core_disable+0xd0/0xd8 (P)
     clk_disable+0x2c/0x44
     rsnd_adg_clk_control+0x80/0xf4

According to Geert, it happened only 7 times during the last 2 years.
So I have reproduced the issue and created patch by Intentionally making
an error.

Link: https://lore.kernel.org/r/CAMuHMdVUKpO2rsia+36BLFFwdMapE8LrYS0duyd0FmrxDvwEfg@xxxxxxxxxxxxxx
Reported-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>
---
 sound/soc/renesas/rcar/adg.c  | 28 +++++++++++++++++++++++-----
 sound/soc/renesas/rcar/core.c |  4 +---
 sound/soc/renesas/rcar/rsnd.h |  2 +-
 3 files changed, 25 insertions(+), 9 deletions(-)

diff --git a/sound/soc/renesas/rcar/adg.c b/sound/soc/renesas/rcar/adg.c
index 0f190abf00e75..191f212d338c2 100644
--- a/sound/soc/renesas/rcar/adg.c
+++ b/sound/soc/renesas/rcar/adg.c
@@ -374,12 +374,12 @@ int rsnd_adg_ssi_clk_try_start(struct rsnd_mod *ssi_mod, unsigned int rate)
 	return 0;
 }
 
-void rsnd_adg_clk_control(struct rsnd_priv *priv, int enable)
+int rsnd_adg_clk_control(struct rsnd_priv *priv, int enable)
 {
 	struct rsnd_adg *adg = rsnd_priv_to_adg(priv);
 	struct rsnd_mod *adg_mod = rsnd_mod_get(adg);
 	struct clk *clk;
-	int i;
+	int ret = 0, i;
 
 	if (enable) {
 		rsnd_mod_bset(adg_mod, BRGCKR, 0x80770000, adg->ckr);
@@ -389,18 +389,33 @@ void rsnd_adg_clk_control(struct rsnd_priv *priv, int enable)
 
 	for_each_rsnd_clkin(clk, adg, i) {
 		if (enable) {
-			clk_prepare_enable(clk);
+			ret = clk_prepare_enable(clk);
 
 			/*
 			 * We shouldn't use clk_get_rate() under
 			 * atomic context. Let's keep it when
 			 * rsnd_adg_clk_enable() was called
 			 */
+			if (ret < 0)
+				break;
+
 			adg->clkin_rate[i] = clk_get_rate(clk);
 		} else {
-			clk_disable_unprepare(clk);
+			if (adg->clkin_rate[i])
+				clk_disable_unprepare(clk);
+
+			adg->clkin_rate[i] = 0;
 		}
 	}
+
+	/*
+	 * rsnd_adg_clk_enable() might return error (_disable() will not).
+	 * We need to rollback in such case
+	 */
+	if (ret < 0)
+		rsnd_adg_clk_disable(priv);
+
+	return ret;
 }
 
 static struct clk *rsnd_adg_create_null_clk(struct rsnd_priv *priv,
@@ -753,7 +768,10 @@ int rsnd_adg_probe(struct rsnd_priv *priv)
 	if (ret)
 		return ret;
 
-	rsnd_adg_clk_enable(priv);
+	ret = rsnd_adg_clk_enable(priv);
+	if (ret)
+		return ret;
+
 	rsnd_adg_clk_dbg_info(priv, NULL);
 
 	return 0;
diff --git a/sound/soc/renesas/rcar/core.c b/sound/soc/renesas/rcar/core.c
index e2234928c9e88..d3709fd0409e4 100644
--- a/sound/soc/renesas/rcar/core.c
+++ b/sound/soc/renesas/rcar/core.c
@@ -2086,9 +2086,7 @@ static int __maybe_unused rsnd_resume(struct device *dev)
 {
 	struct rsnd_priv *priv = dev_get_drvdata(dev);
 
-	rsnd_adg_clk_enable(priv);
-
-	return 0;
+	return rsnd_adg_clk_enable(priv);
 }
 
 static const struct dev_pm_ops rsnd_pm_ops = {
diff --git a/sound/soc/renesas/rcar/rsnd.h b/sound/soc/renesas/rcar/rsnd.h
index 3c164d8e3b16b..a5f54b65313c4 100644
--- a/sound/soc/renesas/rcar/rsnd.h
+++ b/sound/soc/renesas/rcar/rsnd.h
@@ -608,7 +608,7 @@ int rsnd_adg_set_cmd_timsel_gen2(struct rsnd_mod *cmd_mod,
 				 struct rsnd_dai_stream *io);
 #define rsnd_adg_clk_enable(priv)	rsnd_adg_clk_control(priv, 1)
 #define rsnd_adg_clk_disable(priv)	rsnd_adg_clk_control(priv, 0)
-void rsnd_adg_clk_control(struct rsnd_priv *priv, int enable);
+int rsnd_adg_clk_control(struct rsnd_priv *priv, int enable);
 void rsnd_adg_clk_dbg_info(struct rsnd_priv *priv, struct seq_file *m);
 
 /*
-- 
2.43.0