Fallback to sysfs to control backlight if vbetool fails

Change-type: minor
Signed-off-by: Rahul Thakoor <[email protected]>

Author: rahul-thakoor

scheduler/scripts/amd64/backlight_off.sh

@@ -1,3 +1,9 @@
 #!/bin/bash
 
-/usr/sbin/vbetool dpms off
+/usr/sbin/vbetool dpms off 2>/dev/null
+
+# fallback to sysfs if vbetool fails
+if [ $? -ne 0 ]; then
+    # source https://unix.stackexchange.com/a/504839 
+    echo -n 4 > /sys/class/backlight/*/bl_power
+fi

scheduler/scripts/amd64/backlight_on.sh

@@ -1,3 +1,9 @@
 #!/bin/bash
 
-/usr/sbin/vbetool dpms on
+/usr/sbin/vbetool dpms on 2>/dev/null
+
+# fallback to sysfs if vbetool fails
+if [ $? -ne 0 ]; then
+    # source: https://unix.stackexchange.com/a/504839
+    echo -n 0 > /sys/class/backlight/*/bl_power
+fi