Re: [PATCH v2 4/7] dma-helpers: chunk dma_blk_cb at IOV_MAX

[Jesper Wendel Devantier <foss@defmacro.it>]

On 2026-08-19T17:24:06+02:00, Daniel Gomez <da.gomez@kernel.org> wrote:
> From: Daniel Gomez <da.gomez@samsung.com>
>
> dma_blk_cb() submits dbs->iov to io_func() in one shot, so callers
> must keep dbs->iov.niov below IOV_MAX or the host preadv()/pwritev()
> rejects the call.
>
> Break the accumulation loop when niov reaches IOV_MAX. The existing
> re-entry path resumes mapping and submits a follow-up chunk under
> the same AIOCB, so callers no longer carry that constraint.
>
> Suggested-by: Klaus Jensen <k.jensen@samsung.com>
> Signed-off-by: Daniel Gomez <da.gomez@samsung.com>
> ---
>  system/dma-helpers.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/system/dma-helpers.c b/system/dma-helpers.c
> index d4fd33a3d4c..613fa548669 100644
> --- a/system/dma-helpers.c
> +++ b/system/dma-helpers.c
> @@ -175,6 +175,9 @@ static void dma_blk_cb(void *opaque, int ret)
>              dbs->sg_cur_byte = 0;
>              ++dbs->sg_cur_index;
>          }
> +        if (dbs->iov.niov >= IOV_MAX) {
> +            break;
> +        }
>      }
>  
>      if (dbs->iov.size == 0) {
>
> -- 
> 2.55.0
>
>
>

Acked-by: Jesper Wendel Devantier <foss@defmacro.it>