[PATCH] ASoC: fsl_xcvr: Fix channel swap issue with ARC

With pause and resume test for ARC, there is occasionally
channel swap issue. The reason is that currently driver set
the DPATH out of reset first, then start the DMA, the first
data got from FIFO may not be the Left channel.

Moving DPATH out of reset operation after the dma enablement
to fix this issue.

Fixes: 28564486866f ("ASoC: fsl_xcvr: Add XCVR ASoC CPU DAI driver")
Signed-off-by: Shengjiu Wang <redacted>
---
 sound/soc/fsl/fsl_xcvr.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/sound/soc/fsl/fsl_xcvr.c b/sound/soc/fsl/fsl_xcvr.c
index 31c5ee641fe7..6e67033b6cde 100644
--- a/sound/soc/fsl/fsl_xcvr.c
+++ b/sound/soc/fsl/fsl_xcvr.c

@@ -487,8 +487,9 @@ static int fsl_xcvr_prepare(struct snd_pcm_substream *substream,
 		return ret;
 	}
 
-	/* clear DPATH RESET */
+	/* set DPATH RESET */
 	m_ctl |= FSL_XCVR_EXT_CTRL_DPTH_RESET(tx);
+	v_ctl |= FSL_XCVR_EXT_CTRL_DPTH_RESET(tx);
 	ret = regmap_update_bits(xcvr->regmap, FSL_XCVR_EXT_CTRL, m_ctl, v_ctl);
 	if (ret < 0) {
 		dev_err(dai->dev, "Error while setting EXT_CTRL: %d\n", ret);

@@ -590,10 +591,6 @@ static void fsl_xcvr_shutdown(struct snd_pcm_substream *substream,
 		val  |= FSL_XCVR_EXT_CTRL_CMDC_RESET(tx);
 	}
 
-	/* set DPATH RESET */
-	mask |= FSL_XCVR_EXT_CTRL_DPTH_RESET(tx);
-	val  |= FSL_XCVR_EXT_CTRL_DPTH_RESET(tx);
-
 	ret = regmap_update_bits(xcvr->regmap, FSL_XCVR_EXT_CTRL, mask, val);
 	if (ret < 0) {
 		dev_err(dai->dev, "Err setting DPATH RESET: %d\n", ret);

@@ -643,6 +640,16 @@ static int fsl_xcvr_trigger(struct snd_pcm_substream *substream, int cmd,
 			dev_err(dai->dev, "Failed to enable DMA: %d\n", ret);
 			return ret;
 		}
+
+		/* clear DPATH RESET */
+		ret = regmap_update_bits(xcvr->regmap, FSL_XCVR_EXT_CTRL,
+					 FSL_XCVR_EXT_CTRL_DPTH_RESET(tx),
+					 0);
+		if (ret < 0) {
+			dev_err(dai->dev, "Failed to clear DPATH RESET: %d\n", ret);
+			return ret;
+		}
+
 		break;
 	case SNDRV_PCM_TRIGGER_STOP:
 	case SNDRV_PCM_TRIGGER_SUSPEND:

-- 
2.17.1

On Fri, 10 Sep 2021 17:18:30 +0800, Shengjiu Wang wrote:

With pause and resume test for ARC, there is occasionally
channel swap issue. The reason is that currently driver set
the DPATH out of reset first, then start the DMA, the first
data got from FIFO may not be the Left channel.

Moving DPATH out of reset operation after the dma enablement
to fix this issue.

[...]

Applied to

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

Thanks!

[1/1] ASoC: fsl_xcvr: Fix channel swap issue with ARC
      commit: 74b7ee0e7b61838a0a161a84d105aeff0d042646

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