Build: downgrade kernel to fix 8821cu driver

.github/workflows/lo-test.yml

@@ -52,7 +52,6 @@ jobs:
  LOOP_DEVICE=$(losetup -f) && echo "LOOP_DEVICE=$LOOP_DEVICE" >> $GITHUB_ENV
  sudo losetup -P --direct-io $LOOP_DEVICE lede.img
  mkdir lede && sudo mount -o nossd,compress=zstd $LOOP_DEVICE lede
- [ $BRANCH != 'master' ] && BRANCH='openwrt-18.06-k5.4'
  if [ -d 'lede/.git' ]; then
  cd lede && rm -f zerospace && git config --local user.email "[email protected]" && git config --local user.name "GitHub Action"
  git fetch && git reset --hard origin/$BRANCH && git clean -df

scripts/patches.sh

@@ -81,10 +81,12 @@ sed -i '/uci commit luci/i\uci set luci.main.mediaurlbase="/luci-static/argon"'
 sed -i '/182.140.223.146/d;/\.cn\//d;/tencent/d' scripts/download.pl
 
 # add r1s support to Lean's repo
-if [ $DEVICE == 'r1s' ]; then
+if [[ $DEVICE == 'r1s' ]]; then
 cd ~ && git clone -b openwrt-21.02 https://github.com/immortalwrt/immortalwrt && cd immortalwrt
-git log --grep r1s -i | grep '^commit ' | head -n -2 | cut -d' ' -f2 | tac | xargs git show | sed '0,/UENV/s//ATF/' > r1s.diff
-git show 124116564e8a6081e79cb2e87b0d87b2af99c583 >> r1s.diff
-cd ~/lede && chmod +x target/linux/sunxi/base-files/etc/board.d/* && git apply ~/immortalwrt/r1s.diff
-echo "\nCONFIG_ARM_ALLWINNER_SUN50I_CPUFREQ_NVMEM=y\nCONFIG_ARM_SCPI_CPUFREQ=y" >> target/linux/sunxi/cortexa53/config-5.4
+ git log --grep r1s -i | grep '^commit ' | head -n -2 | cut -d' ' -f2 | tac | xargs git show | sed '0,/UENV/s//ATF/' > r1s.diff
+ git show 124116564e8a6081e79cb2e87b0d87b2af99c583 >> r1s.diff
+ cd ~/lede && chmod +x target/linux/sunxi/base-files/etc/board.d/* && git apply ~/immortalwrt/r1s.diff
+ echo "\nCONFIG_ARM_ALLWINNER_SUN50I_CPUFREQ_NVMEM=y\nCONFIG_ARM_SCPI_CPUFREQ=y" >> target/linux/sunxi/cortexa53/config-5.4
+elif [[ $DEVICE == 'r2s' -o $DEVICE == 'r2c' -o $DEVICE == 'r1p' -o $DEVICE == 'r1p-lts' ]]; then
+ sed -i 's/5.15/5.4/g' target/linux/rockchip/Makefile
 fi