[PATCH V2 1/8] dmaengine: zynqmp_dma: Fix PM rollback on sw_desc_pool alloc failure

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

If sw_desc_pool allocation fails after pm_runtime_resume_and_get()
succeeds in zynqmp_dma_alloc_chan_resources(), the error path returns
without dropping the runtime PM reference.

Route that failure path through err_pm so the runtime PM reference is
balanced before returning the error.

Fixes: 8982d48af36d ("dmaengine: zynqmp_dma: Fix PM reference leak in zynqmp_dma_alloc_chan_resourc()")
Signed-off-by: Golla Nagendra <nagendra.golla@amd.com>
---
changes in v2:
- Reworked the patch so sw_desc_pool allocation failure goes through
  err_pm, ensuring the runtime PM reference is dropped before returning
  the error
- Updated commit description to match the new behavior
---
 drivers/dma/xilinx/zynqmp_dma.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/xilinx/zynqmp_dma.c b/drivers/dma/xilinx/zynqmp_dma.c
index f6a812e49ddc..9f1e69700dd0 100644
--- a/drivers/dma/xilinx/zynqmp_dma.c
+++ b/drivers/dma/xilinx/zynqmp_dma.c
@@ -483,8 +483,10 @@ static int zynqmp_dma_alloc_chan_resources(struct dma_chan *dchan)
 		return ret;
 
 	chan->sw_desc_pool = kzalloc_objs(*desc, ZYNQMP_DMA_NUM_DESCS);
-	if (!chan->sw_desc_pool)
-		return -ENOMEM;
+	if (!chan->sw_desc_pool) {
+		ret = -ENOMEM;
+		goto err_pm;
+	}
 
 	chan->idle = true;
 	chan->desc_free_cnt = ZYNQMP_DMA_NUM_DESCS;
@@ -516,6 +518,10 @@ static int zynqmp_dma_alloc_chan_resources(struct dma_chan *dchan)
 	}
 
 	return ZYNQMP_DMA_NUM_DESCS;
+
+err_pm:
+	pm_runtime_put_autosuspend(chan->dev);
+	return ret;
 }
 
 /**
-- 
2.44.4