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

From: Tudor.Ambarus
Date: Tue Aug 02 2022 - 07:03:53 EST


On 7/28/22 10:40, Tudor Ambarus 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")

Reported-by: Peter Rosin <peda@xxxxxxxxxx>

> Signed-off-by: Tudor Ambarus <tudor.ambarus@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;
>


--
Cheers,
ta