[PATCH] iio: adc: nxp-sar-adc: Fix DMA channel leak in trigger mode

[Felix Gu]

The DMA channel was requested in nxp_sar_adc_buffer_postenable() but
was only released in nxp_sar_adc_buffer_software_do_predisable().
This caused a DMA channel resource leak when operating in trigger mode.

Fix this by moving dma_request_chan() from
nxp_sar_adc_buffer_postenable() into
nxp_sar_adc_buffer_software_do_postenable(), ensuring the DMA channel
is only requested in software mode.

Fixes: 4434072a893e ("iio: adc: Add the NXP SAR ADC support for the s32g2/3 platforms")
Signed-off-by: Felix Gu <ustc.gu@xxxxxxxxx>
---
 drivers/iio/adc/nxp-sar-adc.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/iio/adc/nxp-sar-adc.c b/drivers/iio/adc/nxp-sar-adc.c
index 9efa883c277d..890c8ef3132f 100644
--- a/drivers/iio/adc/nxp-sar-adc.c
+++ b/drivers/iio/adc/nxp-sar-adc.c
@@ -718,6 +718,10 @@ static int nxp_sar_adc_buffer_software_do_postenable(struct iio_dev *indio_dev)
 	struct nxp_sar_adc *info = iio_priv(indio_dev);
 	int ret;
 
+	info->dma_chan = dma_request_chan(indio_dev->dev.parent, "rx");
+	if (IS_ERR(info->dma_chan))
+		return PTR_ERR(info->dma_chan);
+
 	nxp_sar_adc_dma_channels_enable(info, *indio_dev->active_scan_mask);
 
 	nxp_sar_adc_dma_cfg(info, true);
@@ -738,7 +742,7 @@ static int nxp_sar_adc_buffer_software_do_postenable(struct iio_dev *indio_dev)
 out_dma_channels_disable:
 	nxp_sar_adc_dma_cfg(info, false);
 	nxp_sar_adc_dma_channels_disable(info, *indio_dev->active_scan_mask);
-
+	dma_release_channel(info->dma_chan);
 	return ret;
 }
 
@@ -765,10 +769,6 @@ static int nxp_sar_adc_buffer_postenable(struct iio_dev *indio_dev)
 	unsigned long channel;
 	int ret;
 
-	info->dma_chan = dma_request_chan(indio_dev->dev.parent, "rx");
-	if (IS_ERR(info->dma_chan))
-		return PTR_ERR(info->dma_chan);
-
 	info->channels_used = 0;
 
 	/*

---
base-commit: d4906ae14a5f136ceb671bb14cedbf13fa560da6
change-id: 20260222-nxp-sar-adc-1-bca71f089bc8

Best regards,
-- 
Felix Gu <ustc.gu@xxxxxxxxx>