meta-ampere: ampere-usbnet: Add delay and restart policy

When ampere-usbnet starts too soon, phosphor-networkd does not yet sync
the MAC address from inventory to u-boot, making ampere-usbnet fail.
This commit updates the service to restart 3 times, with a 5s delay
between restarts, on failure of invalid MAC or no MAC Address available.

Tested:
1. When FRU has valid MAC address, usb should be configured correctly:
       [   62.986382] configfs-gadget.usbnet gadget.0: HOST MAC 02:e2:84:8f:e3:56
       [   62.993978] configfs-gadget.usbnet gadget.0: MAC 06:e2:84:8f:e3:56

 - Check MAC Address using ifconfig:
       root@mtmitchell:~# ifconfig usb0 | grep HWaddr
       usb0      Link encap:Ethernet  HWaddr 06:E2:84:8F:E3:56

2. When FRU has invalid MAC address, usb should be configured with a
   random MAC address after three restarts:

       [   63.417629] configfs-gadget.usbnet gadget.0: HOST MAC 02:c2:49:a6:09:3b
       [   63.425133] configfs-gadget.usbnet gadget.0: MAC 06:c2:49:a6:09:3b
       [   69.017538] configfs-gadget.usbnet gadget.0: HOST MAC 02:c2:49:a6:09:3b
       [   69.025012] configfs-gadget.usbnet gadget.0: MAC 06:c2:49:a6:09:3b
       [   74.530780] configfs-gadget.usbnet gadget.0: HOST MAC 02:c2:49:a6:09:3b
       [   74.538353] configfs-gadget.usbnet gadget.0: MAC 06:c2:49:a6:09:3b

  - Check MAC Address using ifconfig:
       root@mtmitchell:~# ifconfig usb0 | grep HWaddr
       usb0      Link encap:Ethernet  HWaddr 06:C2:49:A6:09:3B

  - u-boot env should be unset:
       root@mtmitchell:~# fw_printenv -n ethaddr
       ## Error: "ethaddr" not defined

Change-Id: If10045485bfd8d6803d6df305805924284740889
Signed-off-by: Khang Nguyen <khangng@amperecomputing.com>
Signed-off-by: Thang Q. Nguyen <thang@os.amperecomputing.com>

2 files changed, 21 insertions, 15 deletions

diff --git a/meta-ampere/meta-common/recipes-ampere/network/ampere-usbnet/ampere-usbnet.service b/meta-ampere/meta-common/recipes-ampere/network/ampere-usbnet/ampere-usbnet.service
index 3499543258..461d423ad4 100644
--- a/meta-ampere/meta-common/recipes-ampere/network/ampere-usbnet/ampere-usbnet.service
+++ b/meta-ampere/meta-common/recipes-ampere/network/ampere-usbnet/ampere-usbnet.service
@@ -1,12 +1,14 @@
 [Unit]
 Description=Ampere Ethernet over USB gadget device
-After=phosphor-ipmi-host.service
+After=multi-user.target
+StartLimitIntervalSec=20
+StartLimitBurst=3
 
 [Service]
-Type=oneshot
-RemainAfterExit=yes
 ExecStart=/usr/sbin/ampere_usbnet.sh
-ExecStop=/usr/bin/usb-ctrl ecm usbnet off
+Restart=on-failure
+RestartMode=direct
+RestartSec=5
 
 [Install]
 WantedBy=multi-user.target
diff --git a/meta-ampere/meta-common/recipes-ampere/network/ampere-usbnet/ampere_usbnet.sh b/meta-ampere/meta-common/recipes-ampere/network/ampere-usbnet/ampere_usbnet.sh
index ca9357fa3a..fb886c2eab 100644
--- a/meta-ampere/meta-common/recipes-ampere/network/ampere-usbnet/ampere_usbnet.sh
+++ b/meta-ampere/meta-common/recipes-ampere/network/ampere-usbnet/ampere_usbnet.sh
@@ -1,18 +1,22 @@
 #!/bin/bash
 
-ENV_MAC_ADDR=$(fw_printenv ethaddr eth1addr)
+# Get MAC Address from uboot, or fallback to a random
+ENV_MAC_ADDR=
+ENV_MAC_ADDR=${ENV_MAC_ADDR:-"$(fw_printenv -n ethaddr)"}
+ENV_MAC_ADDR=${ENV_MAC_ADDR:-"$(fw_printenv -n eth1addr)"}
+MAC_ADDR=${ENV_MAC_ADDR:-"F8:C2:49:A6:09:3B"}
 
-MAC_ADDR=$(echo "$ENV_MAC_ADDR" | cut -d "=" -f 2)
-
-if [ -n "$MAC_ADDR" ]; then
-	# Generate MAC Address from eth1addr using locally administered MAC
-	# https://en.wikipedia.org/wiki/MAC_address#Universal_vs._local_(U/L_bit
-	SUBMAC=$(echo "$MAC_ADDR" | cut -d ":" -f 2-6)
-	/usr/bin/usb-ctrl ecm usbnet on "06:$SUBMAC" "02:$SUBMAC"
-else
-	/usr/bin/usb-ctrl ecm usbnet on
-fi
+# Generate MAC Address using locally administered MAC
+# https://en.wikipedia.org/wiki/MAC_address#Universal_vs._local_(U/L_bit
+SUBMAC=$(echo "$MAC_ADDR" | cut -d ":" -f 2-5)
+/usr/bin/usb-ctrl ecm usbnet off
+/usr/bin/usb-ctrl ecm usbnet on "06:$SUBMAC:01" "06:$SUBMAC:00"
 
 # Use NCM (Ethernet) Gadget instead of FunctionFS Gadget
 echo 0x0103 > /sys/kernel/config/usb_gadget/usbnet/idProduct
 echo "OpenBMC usbnet Device" > /sys/kernel/config/usb_gadget/usbnet/strings/0x409/product
+
+if [ "$MAC_ADDR" != "$ENV_MAC_ADDR" ]; then
+	# fail and wait for systemd to restart this service
+	exit 1
+fi