disk group

userspace/root/usr/comma/comma-init.sh

@@ -127,6 +127,12 @@ function init_filesystems (
   mount_fs tmpfs /rwtmp tmpfs rw,nosuid,nodev,size=100M,mode=1777 &
   wait
 
+  for path in /dev/sd[a-f]*; do
+    [[ -b "$path" ]] || continue
+    chgrp disk "$path"
+    chmod 0660 "$path"
+  done
+
   # rmt_storage and qseecomd are the only users of /dev/block/bootdevice/by-name.
   mkdir -p /dev/block/bootdevice/by-name
   ln -sf /dev/sda1 /dev/block/bootdevice/by-name/ssd

userspace/root/usr/comma/lte/lte.sh

@@ -55,7 +55,8 @@ function setup_modem_ttys {
         iface="${iface%/*}"
       done
 
-      [[ -r "$iface/bInterfaceNumber" && "$(< "${iface%:*}/idVendor")" == "2c7c" ]] || continue
+      [[ -r "$iface/bInterfaceNumber" && -r "${iface%:*}/idVendor" ]] || continue
+      [[ "$(< "${iface%:*}/idVendor")" == "2c7c" ]] || continue
       case "$(< "$iface/bInterfaceNumber")" in
         02) ln -sfn "/dev/$name" /dev/modem_at0 ;;
         03) ln -sfn "/dev/$name" /dev/modem_at1 ;;