diff --git a/device/downstream/linux-samsung-j4lte/APKBUILD b/device/downstream/linux-samsung-j4lte/APKBUILD
index 08a6d231f..46c2f85aa 100644
--- a/device/downstream/linux-samsung-j4lte/APKBUILD
+++ b/device/downstream/linux-samsung-j4lte/APKBUILD
@@ -3,7 +3,7 @@
 maintainer="Hendra Manudinata <hendra@manoedinata.com>"
 pkgname=linux-samsung-j4lte
 pkgver=3.18.140
-pkgrel=2
+pkgrel=3
 pkgdesc="Samsung Galaxy J4 kernel fork"
 arch="aarch64"
 _carch="arm64"
@@ -18,6 +18,7 @@ makedepends="
 	devicepkg-dev
 	findutils
 	flex
+	gcc6
 	openssl-dev
 	perl
 	dtbtool-exynos
@@ -39,10 +40,18 @@ source="
 	0007-fbdev-decon_7570-Initialize-framebuffer-more-late.patch
 	0008-HACK-loop-Force-disable-Direct-I-O-operations.patch
 	linux3.7to4.5-ARM64-remove-Sun-Solaris-style-flag-on-section.patch
+	fix-check-lxdialog.patch
 "
 builddir="$srcdir/$_repository-$_commit"
 _outdir="out"
 
+# Compiler: GCC 6 (not tested with LLVM)
+if [ "${CC:0:5}" != "gcc6-" ]; then
+	CC="gcc6-$CC"
+	HOSTCC="gcc6-gcc"
+	CROSS_COMPILE="gcc6-$CROSS_COMPILE"
+fi
+
 prepare() {
 	default_prepare
 	. downstreamkernel_prepare
@@ -50,7 +59,7 @@ prepare() {
 
 build() {
 	unset LDFLAGS
-	make O="$_outdir" ARCH="$_carch" CC="${CC:-gcc}" \
+	make O="$_outdir" ARCH="$_carch" \
 		KBUILD_BUILD_VERSION="$((pkgrel + 1 ))-postmarketOS"
 
 	# Build dt image with exynos dtbtool
@@ -71,7 +80,7 @@ package() {
 
 sha512sums="
 495e1f9d4c6b4997a5f5faced507493421ecaa104fc6c8affff546f855cc5ea8f535177464f422f5b76db96fbbd1ead2471ef0fd7537659c2041d03c53ede97c  linux-samsung-j4lte-57ffdcdde7e968af314e809cdab6b3ee24bc4d24.tar.gz
-d3f172f271e2bd92ac2167a558590725a4f064b17ade139691eb24db85d21e70a3160a2c14ff6d7b029df4d744154d06ada621b181a653949cc4f3ce0fbfea7b  config-samsung-j4lte.aarch64
+006be1fb59880c0b0eedef7410201718ee88d872d1c48eaac7cf1070f897ea4d67dbd1bd2a83a647cb4a8914c602623c05ba129f7f7c90abc3c268cc67ad15bf  config-samsung-j4lte.aarch64
 fafed0c79633b50f9c62febeb1198bc863ddcaf7d3140bf58b87f574a75a16c1b73d563ce849ab8400030d6700bf64ea3bbb60b5cb86a902696e1bd702a3b276  0001-drivers-leds-ktd2692-Guard-function-calls-under-CONF.patch
 f81dc234b7c37e5c33472a22f96299c435d4e2728e24164dc375abbc80912ce5a9045178deb2338f1f484a52296ad558541c01c101f244a62bf6149e75e0406b  0002-zram-Set-zstd-as-the-default-compressor.patch
 f69b9363ffd543f98f7799256bb3cfccc84623b69d8c7ee3ea291b52cecac7d961d4b491db6b5477bdd527ad3e9cbd738d67647fc074adcd2927b5eb6d2478dd  0003-drivers-usb-u_ether-Force-setting-random-MAC-address.patch
@@ -81,4 +90,5 @@ f0da70e3b5cc498e19430936422cf89476d68a5bbe45d593ab3c8bf353a81401a9133df983d3f1f8
 76700ecaea56f15d4204ff3064e640552eca35d3713fddaaaee204d7bf983ef419c08c7d759ca58430a27bd10d4bda7d1b6a7ec34ba27f503256f4ee6e42649d  0007-fbdev-decon_7570-Initialize-framebuffer-more-late.patch
 ee281f9a6d5bab871d83e02cea6e222c6883e452c7b22ac65b512eca37d007218cad50e297189a4ad46be8d3d5a70f26f62867c75de30387cb4777a0c3a3e5e0  0008-HACK-loop-Force-disable-Direct-I-O-operations.patch
 75545ccd0082a119b9ad95fcef3523c939a5c946f8f3a5c3dde15cee1502f6c1011050a0ad5359426f018bb7ceea1c97a28c7665941bc89f365c8d11065ce0f6  linux3.7to4.5-ARM64-remove-Sun-Solaris-style-flag-on-section.patch
+182be3c596b9cc267ac108d7cf03fc8c328ccc6b36770800e4dcedea8d1bb65e3f5eacf590c2948f58b1418cc60a1670ba77dde8c259e428d158c31b6e1dbaf5  fix-check-lxdialog.patch
 "
diff --git a/device/downstream/linux-samsung-j4lte/config-samsung-j4lte.aarch64 b/device/downstream/linux-samsung-j4lte/config-samsung-j4lte.aarch64
index 410756e95..011244fe6 100644
--- a/device/downstream/linux-samsung-j4lte/config-samsung-j4lte.aarch64
+++ b/device/downstream/linux-samsung-j4lte/config-samsung-j4lte.aarch64
@@ -590,7 +590,7 @@ CONFIG_IP_PNP_RARP=y
 # CONFIG_NET_IPGRE_DEMUX is not set
 CONFIG_NET_IP_TUNNEL=y
 # CONFIG_IP_MROUTE is not set
-# CONFIG_SYN_COOKIES is not set
+CONFIG_SYN_COOKIES=y
 CONFIG_NET_IPVTI=y
 # CONFIG_NET_UDP_TUNNEL is not set
 # CONFIG_NET_FOU is not set
@@ -1593,7 +1593,7 @@ CONFIG_INPUT_MOUSEDEV_PSAUX=y
 CONFIG_INPUT_MOUSEDEV_SCREEN_X=1024
 CONFIG_INPUT_MOUSEDEV_SCREEN_Y=768
 # CONFIG_INPUT_JOYDEV is not set
-CONFIG_INPUT_EVDEV=y
+CONFIG_INPUT_EVDEV=m
 # CONFIG_INPUT_EVBUG is not set
 CONFIG_INPUT_KEYRESET=y
 CONFIG_INPUT_KEYCOMBO=y
@@ -4156,7 +4156,7 @@ CONFIG_NLS_CODEPAGE_437=y
 # CONFIG_NLS_ISO8859_8 is not set
 # CONFIG_NLS_CODEPAGE_1250 is not set
 # CONFIG_NLS_CODEPAGE_1251 is not set
-# CONFIG_NLS_ASCII is not set
+CONFIG_NLS_ASCII=y
 CONFIG_NLS_ISO8859_1=y
 # CONFIG_NLS_ISO8859_2 is not set
 # CONFIG_NLS_ISO8859_3 is not set
diff --git a/device/downstream/linux-samsung-j4lte/fix-check-lxdialog.patch b/device/downstream/linux-samsung-j4lte/fix-check-lxdialog.patch
new file mode 100644
index 000000000..e60a9e4df
--- /dev/null
+++ b/device/downstream/linux-samsung-j4lte/fix-check-lxdialog.patch
@@ -0,0 +1,15 @@
+Fix pre-ANSI C code in check-lxdialog.sh.
+
+diff --git a/scripts/kconfig/lxdialog/check-lxdialog.sh b/scripts/kconfig/lxdialog/check-lxdialog.sh
+index 9d2a4c58..364eaecb 100644
+--- a/scripts/kconfig/lxdialog/check-lxdialog.sh
++++ b/scripts/kconfig/lxdialog/check-lxdialog.sh
+@@ -43,7 +43,7 @@ trap "rm -f $tmp" 0 1 2 3 15
+ check() {
+         $cc -x c - -o $tmp 2>/dev/null <<'EOF'
+ #include CURSES_LOC
+-main() {}
++int main() { return 0; }
+ EOF
+ 	if [ $? != 0 ]; then
+ 	    echo " *** Unable to find the ncurses libraries or the"       1>&2