hw_params() enables mclk unconditionally and hw_free() disables it
unconditionally, but the PCM core does not guarantee 1:1 pairing:
hw_free() can run without hw_params(), and hw_params() can be called
multiple times from the SETUP state. This triggers an "already
disabled" WARN() in the first case and leaks an enable reference in
the second, leaving the clock ungateable.

Guard both sides with the existing mclk_flag, as fsl_sai.c does with
mclk_streams.

Fixes: b47024dc624b ("ASoC: fsl_micfil: Add mclk enable flag")
Signed-off-by: Ștefan Ghețu <stefanghetu9@gmail.com>
---
 sound/soc/fsl/fsl_micfil.c | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/sound/soc/fsl/fsl_micfil.c b/sound/soc/fsl/fsl_micfil.c
index 60ac8eabab9da..5d8f0f76ab46f 100644
--- a/sound/soc/fsl/fsl_micfil.c
+++ b/sound/soc/fsl/fsl_micfil.c
@@ -953,12 +953,17 @@ static int fsl_micfil_reparent_rootclk(struct fsl_micfil *micfil, unsigned int s
 	/* Get root clock */
 	clk = micfil->mclk;
 
-	/* Disable clock first, for it was enabled by pm_runtime */
+	/* Reparent root clock to the PLL matching this sample rate */
 	fsl_asoc_reparent_pll_clocks(dev, clk, micfil->pll8k_clk,
 				     micfil->pll11k_clk, ratio);
-	ret = clk_prepare_enable(clk);
-	if (ret)
-		return ret;
+
+	/* Enable only once; hw_params can be called multiple times */
+	if (!micfil->mclk_flag) {
+		ret = clk_prepare_enable(clk);
+		if (ret)
+			return ret;
+		micfil->mclk_flag = true;
+	}
 
 	return 0;
 }
@@ -991,8 +996,6 @@ static int fsl_micfil_hw_params(struct snd_pcm_substream *substream,
 	if (ret)
 		return ret;
 
-	micfil->mclk_flag = true;
-
 	/* floor(K * CLKDIV) */
 	switch (micfil->quality) {
 	case QUALITY_HIGH:
@@ -1068,8 +1071,10 @@ static int fsl_micfil_hw_free(struct snd_pcm_substream *substream,
 {
 	struct fsl_micfil *micfil = snd_soc_dai_get_drvdata(dai);
 
-	clk_disable_unprepare(micfil->mclk);
-	micfil->mclk_flag = false;
+	if (micfil->mclk_flag) {
+		clk_disable_unprepare(micfil->mclk);
+		micfil->mclk_flag = false;
+	}
 
 	return 0;
 }
-- 
2.53.0

On Sun, 30 Aug 2026 23:51:06 +0300, Ștefan Ghețu wrote:
> ASoC: fsl_micfil: balance mclk enable/disable

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-7.3

Thanks!

[1/1] ASoC: fsl_micfil: balance mclk enable/disable
      https://git.kernel.org/broonie/sound/c/d3dbccfe6afa

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark