Re: [PATCH 1/6] dmaengine: zynqmp_dma: Fix alloc_chan_resources error cleanup

On Thu, Aug 06, 2026 at 06:00:09PM +0530, Golla Nagendra wrote:
> Channel resource allocation can fail after runtime PM has been acquired
> and after part of the descriptor state has been initialized. Without
> proper rollback, the error path leaks a runtime PM reference and, on
> coherent allocation failure, also leaks the software descriptor pool.
>
> Fix this by balancing runtime PM usage before returning an error and
> releasing any partially allocated software descriptor pool.
>
> Fixes: 8982d48af36d ("dmaengine: zynqmp_dma: Fix PM reference leak in zynqmp_dma_alloc_chan_resourc()")
> Signed-off-by: Golla Nagendra <[email protected]>
> ---
>  drivers/dma/xilinx/zynqmp_dma.c | 19 +++++++++++++++----
>  1 file changed, 15 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/dma/xilinx/zynqmp_dma.c b/drivers/dma/xilinx/zynqmp_dma.c
> index f6a812e49ddc..b7c561280694 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;
> @@ -502,8 +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;

This is seperated problem. Need use new patch to fix it.

Frank

> +	}
>
>  	for (i = 0; i < ZYNQMP_DMA_NUM_DESCS; i++) {
>  		desc = chan->sw_desc_pool + i;
> @@ -516,6 +520,13 @@ 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;
>  }
>
>  /**
> --
> 2.43.7
>