rng-tools: Replace obsolete "wants systemd-udev-settle"

The systemd-udev-settle service is listed as obsolete and does in
some cases result in a significant boot time.  Replace that with a
specific wait for the random source hardware device to be loaded.

Before this change:

   Startup finished in 4.025s (kernel) + 2min 13.236s (userspace) = 2min 17.262s
   multi-user.target reached after 2min 8.153s in userspace

After this change:

   Startup finished in 3.956s (kernel) + 13.294s (userspace) = 17.250s
   multi-user.target reached after 9.522s in userspace

(From OE-Core rev: d43e283d749ddd8fd6722411d051f0e505054c6f)

Signed-off-by: Drew Moseley <drew@moseleynet.net>
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 2 insertions, 1 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 568686e80e..0f50890dcb 100644
--- a/meta/recipes-support/rng-tools/rng-tools/rng-tools.service
+++ b/meta/recipes-support/rng-tools/rng-tools/rng-tools.service
@@ -3,7 +3,8 @@ Description=Hardware RNG Entropy Gatherer Daemon
 DefaultDependencies=no
 After=systemd-udev-settle.service
 Before=sysinit.target shutdown.target
-Wants=systemd-udev-settle.service
+Requires=dev-hwrng.device
+After=dev-hwrng.device
 Conflicts=shutdown.target
 
 [Service]