Re: [OE-core][PATCH] rng-tools: Change "Requires" to "WantedBy" for dev-hwrng.device

[Claudius Heine <ch@denx.de>]

Hi Dew.

On 2022-08-15 20:25, drew.moseley@gmail.com wrote:
> From: Drew Moseley <drew@moseleynet.net>
> 
> The previous change to remove the dependency on systemd-udev-settle
> caused boot delays at least on qemu. It seems that change required
> a hwrng device but that's not necessarily available on all platforms.
> 
> This changes the "Requires" to a "WantedBy" as modeled after the
> version of this file on Ubuntu 20.04.
> 
> Signed-off-by: Drew Moseley <drew@moseleynet.net>
> ---
>   meta/recipes-support/rng-tools/rng-tools/rng-tools.service | 3 +--
>   1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/meta/recipes-support/rng-tools/rng-tools/rng-tools.service b/meta/recipes-support/rng-tools/rng-tools/rng-tools.service
> index 0f50890dcb..b013d95932 100644
> --- a/meta/recipes-support/rng-tools/rng-tools/rng-tools.service
> +++ b/meta/recipes-support/rng-tools/rng-tools/rng-tools.service
> @@ -3,8 +3,6 @@ Description=Hardware RNG Entropy Gatherer Daemon
>   DefaultDependencies=no
>   After=systemd-udev-settle.service
>   Before=sysinit.target shutdown.target
> -Requires=dev-hwrng.device
> -After=dev-hwrng.device
>   Conflicts=shutdown.target
>   
>   [Service]
> @@ -32,3 +30,4 @@ SystemCallFilter=@system-service
>   
>   [Install]
>   WantedBy=sysinit.target
> +WantedBy=dev-hwrng.device

This looses the order. Have you tried just replacing `Requires` with 
`Wants`. So something like this:


```

Before=sysinit.target shutdown.target
Wants=dev-hwrng.device
After=dev-hwrng.device
Conflicts=shutdown.target

```

If that still would cause the long waiting time on qemu?

I haven't investigated the qemu issue, but maybe qemu just doesn't 
provide a hardware random source? If it doesn't provide a hardware 
random source, then installing rng-tools on there might also not make sense.

Alternatively maybe just adding a start timeout might solve it?

regards,
Claudius