[PATCH v2] spi: atmel: fix DMA channel and bounce buffer leaks

[Mark Brown]

On Sun, May 17, 2026 at 06:39:54PM +0800, Felix Gu wrote:

> Changes in v2:
> - Switch to devm-managed variants to fix Claudiu Beznea's comment.

The switch to devm is possibly a bit enthusiastic.

> -	host->dma_tx = dma_request_chan(dev, "tx");
> +	host->dma_tx = devm_dma_request_chan(dev, "tx");
>  	if (IS_ERR(host->dma_tx)) {

> -	host->dma_rx = dma_request_chan(dev, "rx");
> +	host->dma_rx = devm_dma_request_chan(dev, "rx");
>  	if (IS_ERR(host->dma_rx)) {
>  		err = PTR_ERR(host->dma_rx);
>  		/*
> @@ -580,12 +581,27 @@ static int atmel_spi_configure_dma(struct spi_controller *host,
>  		 * requested tx channel.
>  		 */
>  		dev_dbg(dev, "No RX DMA channel, DMA is disabled\n");
> -		goto error;
> +		host->dma_rx = NULL;
> +		return err;
>  	}

If the rx allocation fails then instead of jumping to cleanup we'll
return, and since the driver supports PIO operation it'll still be able
to probe...

> -error:
> -	if (!IS_ERR(host->dma_rx))
> -		dma_release_channel(host->dma_rx);
> -	if (!IS_ERR(host->dma_tx))
> -		dma_release_channel(host->dma_tx);

...with the tx DMA channel still allocated.  This is very much an edge
case though, how much it matters is very questionalble.
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