ASoC: adau1372: Fix error handling in adau1372_set_power()

Jihed Chaibi <jihed.chaibi.dev@gmail.com> says:

adau1372_set_power() had two related error handling issues in its enable
path: clk_prepare_enable() was called but its return value discarded, and
adau1372_enable_pll() was a void function that silently swallowed lock
failures, leaving mclk enabled and adau1372->enabled set to true despite
the device being in a broken state.

Patch 1 fixes the unchecked clk_prepare_enable() by making
adau1372_set_power() return int and propagating the error.

Patch 2 converts adau1372_enable_pll() to return int and adds a full
unwind in adau1372_set_power() if PLL lock fails, reversing the regcache,
GPIO power-down, and clock state.

2 files changed, 27 insertions, 13 deletions

diff --git a/sound/soc/codecs/adau1372.c b/sound/soc/codecs/adau1372.c
index fdee689cae53..d7363f9d53bb 100644
--- a/sound/soc/codecs/adau1372.c
+++ b/sound/soc/codecs/adau1372.c
@@ -762,7 +762,7 @@ static int adau1372_startup(struct snd_pcm_substream *substream, struct snd_soc_
 	return 0;
 }
 
-static void adau1372_enable_pll(struct adau1372 *adau1372)
+static int adau1372_enable_pll(struct adau1372 *adau1372)
 {
 	unsigned int val, timeout = 0;
 	int ret;
@@ -778,19 +778,26 @@ static void adau1372_enable_pll(struct adau1372 *adau1372)
 		timeout++;
 	} while (!(val & 1) && timeout < 3);
 
-	if (ret < 0 || !(val & 1))
+	if (ret < 0 || !(val & 1)) {
 		dev_err(adau1372->dev, "Failed to lock PLL\n");
+		return ret < 0 ? ret : -ETIMEDOUT;
+	}
+
+	return 0;
 }
 
-static void adau1372_set_power(struct adau1372 *adau1372, bool enable)
+static int adau1372_set_power(struct adau1372 *adau1372, bool enable)
 {
 	if (adau1372->enabled == enable)
-		return;
+		return 0;
 
 	if (enable) {
 		unsigned int clk_ctrl = ADAU1372_CLK_CTRL_MCLK_EN;
+		int ret;
 
-		clk_prepare_enable(adau1372->mclk);
+		ret = clk_prepare_enable(adau1372->mclk);
+		if (ret)
+			return ret;
 		if (adau1372->pd_gpio)
 			gpiod_set_value(adau1372->pd_gpio, 0);
 
@@ -804,7 +811,14 @@ static void adau1372_set_power(struct adau1372 *adau1372, bool enable)
 		 * accessed.
 		 */
 		if (adau1372->use_pll) {
-			adau1372_enable_pll(adau1372);
+			ret = adau1372_enable_pll(adau1372);
+			if (ret) {
+				regcache_cache_only(adau1372->regmap, true);
+				if (adau1372->pd_gpio)
+					gpiod_set_value(adau1372->pd_gpio, 1);
+				clk_disable_unprepare(adau1372->mclk);
+				return ret;
+			}
 			clk_ctrl |= ADAU1372_CLK_CTRL_CLKSRC;
 		}
 
@@ -829,6 +843,8 @@ static void adau1372_set_power(struct adau1372 *adau1372, bool enable)
 	}
 
 	adau1372->enabled = enable;
+
+	return 0;
 }
 
 static int adau1372_set_bias_level(struct snd_soc_component *component,
@@ -842,11 +858,9 @@ static int adau1372_set_bias_level(struct snd_soc_component *component,
 	case SND_SOC_BIAS_PREPARE:
 		break;
 	case SND_SOC_BIAS_STANDBY:
-		adau1372_set_power(adau1372, true);
-		break;
+		return adau1372_set_power(adau1372, true);
 	case SND_SOC_BIAS_OFF:
-		adau1372_set_power(adau1372, false);
-		break;
+		return adau1372_set_power(adau1372, false);
 	}
 
 	return 0;
diff --git a/sound/soc/samsung/i2s.c b/sound/soc/samsung/i2s.c
index e9964f0e010a..140907a41a70 100644
--- a/sound/soc/samsung/i2s.c
+++ b/sound/soc/samsung/i2s.c
@@ -1360,10 +1360,10 @@ static int i2s_create_secondary_device(struct samsung_i2s_priv *priv)
 	if (!pdev_sec)
 		return -ENOMEM;
 
-	pdev_sec->driver_override = kstrdup("samsung-i2s", GFP_KERNEL);
-	if (!pdev_sec->driver_override) {
+	ret = device_set_driver_override(&pdev_sec->dev, "samsung-i2s");
+	if (ret) {
 		platform_device_put(pdev_sec);
-		return -ENOMEM;
+		return ret;
 	}
 
 	ret = platform_device_add(pdev_sec);