[PATCH] iio: buffer-dmaengine: fix releasing dma channel on error

From: David Lechner
Date: Tue Jul 23 2024 - 12:32:37 EST


If dma_get_slave_caps() fails, we need to release the dma channel before
returning an error to avoid leaking the channel.

Fixes: 2d6ca60f3284 ("iio: Add a DMAengine framework based buffer")
Signed-off-by: David Lechner <dlechner@xxxxxxxxxxxx>
---
drivers/iio/buffer/industrialio-buffer-dmaengine.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/buffer/industrialio-buffer-dmaengine.c b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
index 12aa1412dfa0..426cc614587a 100644
--- a/drivers/iio/buffer/industrialio-buffer-dmaengine.c
+++ b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
@@ -237,7 +237,7 @@ static struct iio_buffer *iio_dmaengine_buffer_alloc(struct device *dev,

ret = dma_get_slave_caps(chan, &caps);
if (ret < 0)
- goto err_free;
+ goto err_release;

/* Needs to be aligned to the maximum of the minimums */
if (caps.src_addr_widths)
@@ -263,6 +263,8 @@ static struct iio_buffer *iio_dmaengine_buffer_alloc(struct device *dev,

return &dmaengine_buffer->queue.buffer;

+err_release:
+ dma_release_channel(chan);
err_free:
kfree(dmaengine_buffer);
return ERR_PTR(ret);

---
base-commit: 472438c7e0e2261c6737a8321f46ef176eef1c8f
change-id: 20240723-iio-fix-dmaengine-free-on-error-6e6e8b4dd058