Re: [PATCH] mtd: rawnand: atmel: Unmap streaming DMA mappings

[Boris Brezillon]

On Thu, 28 Jul 2022 10:40:14 +0300
Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx> wrote:

> Every dma_map_single() call should have its dma_unmap_single() counterpart,
> because the DMA address space is a shared resource and one could render the
> machine unusable by consuming all DMA addresses.
> 
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: f88fc122cc34 ("mtd: nand: Cleanup/rework the atmel_nand driver")
> Signed-off-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx>

Reviewed-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>

> ---
>  drivers/mtd/nand/raw/atmel/nand-controller.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/mtd/nand/raw/atmel/nand-controller.c b/drivers/mtd/nand/raw/atmel/nand-controller.c
> index 6ef14442c71a..330d2dafdd2d 100644
> --- a/drivers/mtd/nand/raw/atmel/nand-controller.c
> +++ b/drivers/mtd/nand/raw/atmel/nand-controller.c
> @@ -405,6 +405,7 @@ static int atmel_nand_dma_transfer(struct atmel_nand_controller *nc,
>  
>  	dma_async_issue_pending(nc->dmac);
>  	wait_for_completion(&finished);
> +	dma_unmap_single(nc->dev, buf_dma, len, dir);
>  
>  	return 0;
>