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

[Frank Li]

On Fri, Aug 14, 2026 at 10:26:10AM +0530, Golla Nagendra wrote:
> 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 at amd.com>
> ---

Reviewed-by: Frank Li <Frank.Li at nxp.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
>