Re: [PATCH 2/3] accel: ethosu: Fix NPU_OP_ELEMENTWISE validation with scalar

[Anders Roxell]

On Wed, 18 Feb 2026 at 23:22, Rob Herring (Arm) <robh@xxxxxxxxxx> wrote:
>
> The NPU_OP_ELEMENTWISE instruction uses a scalar value for IFM2 if the
> IFM2_BROADCAST "scalar" mode is set. It is a bit (7) on the u65 and
> part of a field (bits 3:0) on the u85. The driver was hardcoded to the
> u85.
>
> Fixes: 5a5e9c0228e6 ("accel: Add Arm Ethos-U NPU driver")
> Signed-off-by: Rob Herring (Arm) <robh@xxxxxxxxxx>

Reviewed-and-Tested-by: Anders Roxell <anders.roxell@xxxxxxxxxx>

> ---
>  drivers/accel/ethosu/ethosu_gem.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/accel/ethosu/ethosu_gem.c b/drivers/accel/ethosu/ethosu_gem.c
> index 473b5f5d7514..a735f860a119 100644
> --- a/drivers/accel/ethosu/ethosu_gem.c
> +++ b/drivers/accel/ethosu/ethosu_gem.c
> @@ -417,7 +417,10 @@ static int ethosu_gem_cmdstream_copy_and_validate(struct drm_device *ddev,
>                                 return ret;
>                         break;
>                 case NPU_OP_ELEMENTWISE:
> -                       use_ifm2 = !((st.ifm2.broadcast == 8) || (param == 5) ||
> +                       use_scale = ethosu_is_u65(edev) ?
> +                                   (st.ifm2.broadcast & 0x80) :
> +                                   (st.ifm2.broadcast == 8);
> +                       use_ifm2 = !(use_scale || (param == 5) ||
>                                 (param == 6) || (param == 7) || (param == 0x24));
>                         use_ifm = st.ifm.broadcast != 8;
>                         ret = calc_sizes_elemwise(ddev, info, cmd, &st, use_ifm, use_ifm2);
>
> --
> 2.51.0
>