[PATCH 2/2] ASoC: mediatek: mt8192: Check runtime resume during probe

[Cássio Gabriel]

The MT8192 AFE probe enables runtime PM temporarily while reinitializing
the regmap cache from hardware, but it uses pm_runtime_get_sync()
without checking the return value. If runtime resume fails, probe keeps
going without the device necessarily being accessible, and
pm_runtime_get_sync() may leave the PM usage count incremented.

The regmap_reinit_cache() failure path also returns before dropping the
temporary PM reference and before clearing pm_runtime_bypass_reg_ctl.

Use pm_runtime_resume_and_get() so resume failures do not leak a usage
count, and clear the temporary bypass flag after dropping the probe PM
reference on all regmap_reinit_cache() outcomes.

Fixes: 125ab5d588b0 ("ASoC: mediatek: mt8192: add platform driver")
Cc: stable at vger.kernel.org
Signed-off-by: Cássio Gabriel <cassiogabrielcontato at gmail.com>
---
 sound/soc/mediatek/mt8192/mt8192-afe-pcm.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/sound/soc/mediatek/mt8192/mt8192-afe-pcm.c b/sound/soc/mediatek/mt8192/mt8192-afe-pcm.c
index 9f5057eeeff9..db0ae44a86af 100644
--- a/sound/soc/mediatek/mt8192/mt8192-afe-pcm.c
+++ b/sound/soc/mediatek/mt8192/mt8192-afe-pcm.c
@@ -2227,15 +2227,19 @@ static int mt8192_afe_pcm_dev_probe(struct platform_device *pdev)
 
 	/* enable clock for regcache get default value from hw */
 	afe_priv->pm_runtime_bypass_reg_ctl = true;
-	pm_runtime_get_sync(dev);
+	ret = pm_runtime_resume_and_get(dev);
+	if (ret) {
+		afe_priv->pm_runtime_bypass_reg_ctl = false;
+		return dev_err_probe(dev, ret, "failed to resume device\n");
+	}
 
 	ret = regmap_reinit_cache(afe->regmap, &mt8192_afe_regmap_config);
-	if (ret)
-		return dev_err_probe(dev, ret, "regmap_reinit_cache fail\n");
-
 	pm_runtime_put_sync(dev);
 	afe_priv->pm_runtime_bypass_reg_ctl = false;
 
+	if (ret)
+		return dev_err_probe(dev, ret, "regmap_reinit_cache fail\n");
+
 	regcache_cache_only(afe->regmap, true);
 	regcache_mark_dirty(afe->regmap);
 

-- 
2.54.0