[PATCH 1/4] common/config: disable udevadm settle if CONFIG_NET is disabled

From: Luis Chamberlain
Date: Tue Jul 27 2021 - 16:10:54 EST


If CONFIG_NET is disabled kobject_uevent_net_broadcast() will be a no-op
and so no uevent are sent and so 'udevadm settle' won't really do
anything for you.

We check for /proc/net to see if CONFIG_NET was enabled.

Signed-off-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
---
common/config | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/common/config b/common/config
index adc16b59..005fd50a 100644
--- a/common/config
+++ b/common/config
@@ -240,7 +240,14 @@ else
UDEV_SETTLE_PROG="$UDEV_SETTLE_PROG settle"
fi
# neither command is available, use sleep 1
-if [ "$UDEV_SETTLE_PROG" == "" ]; then
+#
+# Udev events are sent via netlink to userspace through
+# kobject_uevent_net_broadcast(), and udev in userspace is in charge of
+# handling the events. The command `udevadm settle` just checks if
+# /run/udev/queue is 0, however, a kernel without CONFIG_NET will have
+# kobject_uevent_net_broadcast() be a no-op, and so /run/udev/queue may not
+# exist or always be 0. We check for /proc/net to see CONFIG_NET was enabled.
+if [[ "$UDEV_SETTLE_PROG" == "" || ! -d /proc/net ]]; then
UDEV_SETTLE_PROG="sleep 1"
fi
export UDEV_SETTLE_PROG
--
2.29.2