On Fri, Aug 19, 2022 at 08:07:44AM +0200, Jack Wang wrote:
> dma_map_sg return 0 on error, in case of error set
> EIO as return code.
>
> Cc: Jason Gunthorpe <jgg@xxxxxxxx>
> Cc: Leon Romanovsky <leon@xxxxxxxxxx>
> Cc: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
> Cc: Kees Cook <keescook@xxxxxxxxxxxx>
> Cc: "Håkon Bugge" <haakon.bugge@xxxxxxxxxx>
> Cc: linux-rdma@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Signed-off-by: Jack Wang <jinpu.wang@xxxxxxxxx>
> ---
> drivers/infiniband/hw/mthca/mthca_memfree.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/infiniband/hw/mthca/mthca_memfree.c b/drivers/infiniband/hw/mthca/mthca_memfree.c
> index f2734a5c5f26..44fd5fdf64d5 100644
> --- a/drivers/infiniband/hw/mthca/mthca_memfree.c
> +++ b/drivers/infiniband/hw/mthca/mthca_memfree.c
> @@ -189,7 +189,7 @@ struct mthca_icm *mthca_alloc_icm(struct mthca_dev *dev, int npages,
> chunk->npages,
> DMA_BIDIRECTIONAL);
>
> - if (chunk->nsg <= 0)
> + if (!chunk->nsg)
> goto fail;
> }
>
> @@ -208,7 +208,7 @@ struct mthca_icm *mthca_alloc_icm(struct mthca_dev *dev, int npages,
> chunk->nsg = dma_map_sg(&dev->pdev->dev, chunk->mem,
> chunk->npages, DMA_BIDIRECTIONAL);
>
> - if (chunk->nsg <= 0)
> + if (!chunk->nsg)
> goto fail;
> }
>
> @@ -482,8 +482,9 @@ int mthca_map_user_db(struct mthca_dev *dev, struct mthca_uar *uar,
>
> ret = dma_map_sg(&dev->pdev->dev, &db_tab->page[i].mem, 1,
> DMA_TO_DEVICE);
> - if (ret < 0) {
> + if (!ret) {
This code is not equivalent to original code. mthca didn't count ret == 0
as an error. Most likely, it is a bug, but I don't want to change old and
unmaintained driver without any real need.
Thanks
> unpin_user_page(pages[0]);
> + ret = -EIO;
> goto out;
> }
>
> --
> 2.34.1
>
