[PATCH V2 2/8] dmaengine: zynqmp_dma: Free sw_desc_pool on desc_pool_v alloc failure

[Golla Nagendra <nagendra.golla@amd.com>]

In zynqmp_dma_alloc_chan_resources(), sw_desc_pool is allocated before
desc_pool_v. If dma_alloc_coherent() for desc_pool_v fails, the function
currently exits through the runtime PM rollback path but leaves the
already allocated sw_desc_pool behind.

Add a dedicated err_free_sw_desc_pool label for the desc_pool_v failure
path, free sw_desc_pool there, then fall through to err_pm for
pm_runtime_put_autosuspend().

This keeps the error unwind symmetric and avoids leaking the software
descriptor pool on coherent descriptor allocation failure.

Fixes: b0cc417c1637 ("dmaengine: Add Xilinx zynqmp dma engine driver support")
Signed-off-by: Golla Nagendra <nagendra.golla@amd.com>
---
changes in v2:
- Split this cleanup from the previous combined alloc_chan_resources patch
- Added err_free_sw_desc_pool label for desc_pool_v allocation failure,
  freeing sw_desc_pool before falling through to err_pm
- Updated commit description to match the exact cleanup path
---
 drivers/dma/xilinx/zynqmp_dma.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/xilinx/zynqmp_dma.c b/drivers/dma/xilinx/zynqmp_dma.c
index 9f1e69700dd0..b7c561280694 100644
--- a/drivers/dma/xilinx/zynqmp_dma.c
+++ b/drivers/dma/xilinx/zynqmp_dma.c
@@ -504,8 +504,10 @@ static int zynqmp_dma_alloc_chan_resources(struct dma_chan *dchan)
 					       (2 * ZYNQMP_DMA_DESC_SIZE(chan) *
 					       ZYNQMP_DMA_NUM_DESCS),
 					       &chan->desc_pool_p, GFP_KERNEL);
-	if (!chan->desc_pool_v)
-		return -ENOMEM;
+	if (!chan->desc_pool_v) {
+		ret = -ENOMEM;
+		goto err_free_sw_desc_pool;
+	}
 
 	for (i = 0; i < ZYNQMP_DMA_NUM_DESCS; i++) {
 		desc = chan->sw_desc_pool + i;
@@ -519,6 +521,9 @@ static int zynqmp_dma_alloc_chan_resources(struct dma_chan *dchan)
 
 	return ZYNQMP_DMA_NUM_DESCS;
 
+err_free_sw_desc_pool:
+	kfree(chan->sw_desc_pool);
+	chan->sw_desc_pool = NULL;
 err_pm:
 	pm_runtime_put_autosuspend(chan->dev);
 	return ret;
-- 
2.44.4