[PATCH] dm: make uclass_find_first_device() return error when no defice is found

[Simon Glass]

Hi Masahiro,

On Mon, 24 Feb 2020 at 23:58, Masahiro Yamada
<yamada.masahiro at socionext.com> wrote:
>
> uclass_find_first_device() succeeds even if it cannot find any device.
> So, the caller must check the return code and also *devp is not NULL.
>
> Returning -ENODEV will be sensible in this case.
>
> Signed-off-by: Masahiro Yamada <yamada.masahiro at socionext.com>
> ---
>
> If this patch is acceptable, I want to fold this
> into my pull request because it need it
> for my another patch:
> http://patchwork.ozlabs.org/patch/1238000/
>
>  drivers/core/uclass.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

I sort-of agree and have thought about this a lot.

But what are you doing in the case of uclass_find_next_device()?

Also what about the tests and other code that expects the current behaviour?

>
> diff --git a/drivers/core/uclass.c b/drivers/core/uclass.c
> index 58b19a421091..3580974f3b85 100644
> --- a/drivers/core/uclass.c
> +++ b/drivers/core/uclass.c
> @@ -227,7 +227,7 @@ int uclass_find_first_device(enum uclass_id id, struct udevice **devp)
>         if (ret)
>                 return ret;
>         if (list_empty(&uc->dev_head))
> -               return 0;
> +               return -ENODEV;
>
>         *devp = list_first_entry(&uc->dev_head, struct udevice, uclass_node);
>
> --
> 2.17.1
>

Regards,
Simon