From 560cfa1ca2d67f2415ea0af83828d2cbcfa798ef Mon Sep 17 00:00:00 2001
From: honsma235 <114189750+honsma235@users.noreply.github.com>
Date: Sat, 12 Aug 2023 13:52:27 +0200
Subject: [PATCH] Update real-time capability check for multimacd (#2386)

---
 buildroot-external/overlay/RFD/etc/init.d/S60multimacd | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/buildroot-external/overlay/RFD/etc/init.d/S60multimacd b/buildroot-external/overlay/RFD/etc/init.d/S60multimacd
index 0b3b64a789..049b6992cb 100755
--- a/buildroot-external/overlay/RFD/etc/init.d/S60multimacd
+++ b/buildroot-external/overlay/RFD/etc/init.d/S60multimacd
@@ -82,12 +82,10 @@ start() {
   if [[ -n "${HM_HMIP_DEV}" ]] && [[ -n "${HM_HMRF_DEV}" ]] &&
      ( ( ! echo "${HM_HMIP_DEV}" | grep -q "HMIP-RFUSB" ) || [[ "${HM_HMRF_DEV}" != "HM-CFG-USB-2" ]] ); then
 
-    # we need to check if the system has CONFIG_RT_GROUP_SCHED enabled
-    # and enough cpu.rt_runtime_us shares assigned or otherwise
+    # we need to check if the system allows changing real-time scheduling attributes or otherwise
     # multimacd startup will fail as it uses sched_setscheduler() to
     # raise the real-time priority for processing things with low latency
-    if [[ ! -e /sys/fs/cgroup/cpu/cpu.rt_runtime_us ]] ||
-       [[ $(cat /sys/fs/cgroup/cpu/cpu.rt_runtime_us) -gt 0 ]]; then
+    if /usr/bin/chrt -f 10 echo >/dev/null 2>&1; then
 
       # run init function
       init
@@ -109,7 +107,7 @@ start() {
         echo "ERROR: /dev/eq3loop missing"
       fi
     else
-      echo "ERROR: not enough real-time shares (cpu.rt_runtime_us == 0)"
+      echo "ERROR: real-time scheduling test failed. CONFIG_RT_GROUP_SCHED not set or host kernel unable to utilize sched_setscheduler()"
     fi
   else
     echo "not required"