feat: Power-off fix for the Steam Machine; the kernel pin is optional

Kernels >= 7.2 keep the firmware's S4/S5 wake bit on GPIO pin 18, so the
Steam Machine starts again right after powering off. Steam Machine
support now builds a DKMS module (patches/steamify-fremont-poweroff.c)
that clears it before power-off, for every kernel. The kernel pin is no
longer ticked by default. Module sources and patches move to patches/,
embedded by the single-file build.

lib/cec.sh

@@ -60,8 +60,8 @@ cec_reload_driver() {
 cec_driver_enable() {
     detect_valve_fremont || return 0
     local tmp k
-    if ! pacman -Q dkms >/dev/null 2>&1; then
-        sudo pacman -S --needed --noconfirm dkms || { err "Installing dkms failed."; return 1; }
+    if ! pacman -Q dkms patch >/dev/null 2>&1; then
+        sudo pacman -S --needed --noconfirm dkms patch || { err "Installing dkms failed."; return 1; }
     fi
     install_kernel_headers || return 1
     tmp="$(mktemp -d)"
@@ -72,13 +72,8 @@ cec_driver_enable() {
         err "Downloading Valve's CEC driver failed (or its checksum didn't match)."
         return 1
     fi
-    # amdgpu registers its HDMI notifier without a port name, which only
-    # matches the driver's named lookup ("Port C") if the driver loaded
-    # first; amdgpu loads from the initramfs, so it never does. With a
-    # single CEC port, look it up by device alone.
-    sed -i 's/cec_notifier_cec_adap_register(hdmi_dev, conns\[port_num\],/cec_notifier_cec_adap_register(hdmi_dev, conns[1] ? conns[port_num] : NULL,/' \
-        "$tmp/cros-ec-cec.c"
-    grep -q 'conns\[1\] ? conns\[port_num\] : NULL' "$tmp/cros-ec-cec.c" ||
+    # So it finds amdgpu's HDMI port (see the patch for why).
+    patch_file cros-ec-cec-single-port.patch | patch -s -d "$tmp" -p1 ||
         { rm -rf "$tmp"; err "Patching Valve's CEC driver failed."; return 1; }
     echo 'obj-m += cros-ec-cec.o' >"$tmp/Makefile"
     printf '%s\n' "# Written by Steamify: Valve's cros_ec_cec, which knows the Steam Machine." \

lib/common.sh

@@ -6,6 +6,9 @@ c_reset="\033[0m"; c_bold="\033[1m"; c_green="\033[32m"; c_yellow="\033[33m"; c_
 
 info()  { echo -e "${c_cyan}[INFO]${c_reset} $*"; }
 ok()    { echo -e "${c_green}[OK]${c_reset} $*"; }
+# patch_file <name>: a file from patches/ (module sources, patches). The
+# single-file build replaces this with one that has them embedded.
+patch_file() { cat "$SCRIPT_DIR/patches/$1"; }
 warn()  { echo -e "${c_yellow}[WARN]${c_reset} $*"; }
 err()   { echo -e "${c_red}[ERROR] $*${c_reset}" >&2; }
 ask_yn() {

lib/fremont-poweroff.sh

@@ -0,0 +1,57 @@
+#!/bin/bash
+# Part of "Steam Machine support": the Steam Machine powers off instead of
+# booting up again, on every kernel. Since Linux 7.2 ("pinctrl-amd: Don't
+# clear S4 wake bits at probe") the S4/S5 wake bit the firmware leaves set
+# on GPIO pin 18 stays set, and the machine starts again right after
+# powering off (the reason for the kernel pin). Valve's kernel clears it at
+# probe on Fremont, in a patch not meant for upstream, so CachyOS won't get
+# it. A small module (patches/steamify-fremont-poweroff.c) clears it right
+# before power-off; DKMS builds it for every kernel. On kernels that clear it themselves it does nothing.
+# Sourced by steamify.sh; not meant to be run on its own.
+
+POWEROFF_DKMS_NAME=steamify-fremont-poweroff
+POWEROFF_DKMS_VER=1
+POWEROFF_DKMS_SRC="/usr/src/$POWEROFF_DKMS_NAME-$POWEROFF_DKMS_VER"
+POWEROFF_MODULES_LOAD=/etc/modules-load.d/steamify-fremont-poweroff.conf
+
+poweroff_fix_installed() { [[ -f "$POWEROFF_DKMS_SRC/dkms.conf" && -f "$POWEROFF_MODULES_LOAD" ]]; }
+
+poweroff_fix_enable() {
+    detect_valve_fremont || return 0
+    local tmp k
+    if ! pacman -Q dkms >/dev/null 2>&1; then
+        sudo pacman -S --needed --noconfirm dkms || { err "Installing dkms failed."; return 1; }
+    fi
+    install_kernel_headers || return 1
+    tmp="$(mktemp -d)"
+    patch_file "$POWEROFF_DKMS_NAME.c" > "$tmp/$POWEROFF_DKMS_NAME.c"
+    echo "obj-m += $POWEROFF_DKMS_NAME.o" >"$tmp/Makefile"
+    printf '%s\n' "# Written by Steamify: the Steam Machine powers off instead of booting up again." \
+        "PACKAGE_NAME=\"$POWEROFF_DKMS_NAME\"" "PACKAGE_VERSION=\"$POWEROFF_DKMS_VER\"" \
+        "BUILT_MODULE_NAME[0]=\"$POWEROFF_DKMS_NAME\"" 'DEST_MODULE_LOCATION[0]="/updates/dkms"' \
+        'AUTOINSTALL="yes"' >"$tmp/dkms.conf"
+    sudo dkms remove "$POWEROFF_DKMS_NAME/$POWEROFF_DKMS_VER" --all >/dev/null 2>&1
+    sudo rm -rf "$POWEROFF_DKMS_SRC"
+    sudo install -d "$POWEROFF_DKMS_SRC" &&
+        sudo install -m644 "$tmp"/{"$POWEROFF_DKMS_NAME.c",Makefile,dkms.conf} "$POWEROFF_DKMS_SRC/"
+    rm -rf "$tmp"
+    sudo dkms add "$POWEROFF_DKMS_NAME/$POWEROFF_DKMS_VER" >/dev/null ||
+        { err "Adding the power-off fix to DKMS failed."; return 1; }
+    for k in /usr/lib/modules/*/build; do
+        k="$(basename "$(dirname "$k")")"
+        info "Building the power-off fix for $k..."
+        sudo dkms install "$POWEROFF_DKMS_NAME/$POWEROFF_DKMS_VER" -k "$k" >/dev/null ||
+            warn "Building the power-off fix for $k failed; with that kernel it may start again after shutting down."
+    done
+    echo "$POWEROFF_DKMS_NAME" | sudo tee "$POWEROFF_MODULES_LOAD" >/dev/null
+    sudo modprobe "$POWEROFF_DKMS_NAME" 2>/dev/null
+    return 0
+}
+
+poweroff_fix_disable() {
+    sudo rm -f "$POWEROFF_MODULES_LOAD"
+    sudo modprobe -r "$POWEROFF_DKMS_NAME" 2>/dev/null
+    [[ -d "$POWEROFF_DKMS_SRC" ]] || return 0
+    sudo dkms remove "$POWEROFF_DKMS_NAME/$POWEROFF_DKMS_VER" --all >/dev/null 2>&1
+    sudo rm -rf "$POWEROFF_DKMS_SRC"
+}

lib/menu.sh

@@ -16,7 +16,7 @@ declare -A PARENT=([boot]=gaming [kpin]=machine [hdmi]=machine [bios]=machine)
 # upset other devices on the TV, even on SteamOS), except on a Steam Machine,
 # which has CEC like on SteamOS. HDMI refresh boost needs someone at the
 # screen to confirm each step.
-NO_PRESELECT=(boot cec hdmi)
+NO_PRESELECT=(boot cec kpin hdmi)
 
 declare -A LABEL=(
     [gaming]="SteamOS conversion: boot into gaming mode, Steam on the desktop"
@@ -27,7 +27,7 @@ declare -A LABEL=(
     [launcher]="Steamify shortcut: the app on the desktop, Steamify Terminal in the launcher"
     [cec]="HDMI-CEC: use Steam with the TV remote, TV on/off with the PC (experimental)"
     [machine]="Steam Machine support: LED bar driver, hardware settings in Steam"
-    [kpin]="Pin the kernel to $PINNED_KERNEL_VER (fixes rebooting after shutdown)"
+    [kpin]="Pin the kernel to $PINNED_KERNEL_VER (optional, stays on an older kernel)"
     [hdmi]="HDMI refresh boost: highest refresh your HDMI display runs"
     [bios]="Update BIOS"
 )
@@ -72,6 +72,8 @@ detect_components() {
     done
     # HDMI-CEC set up by an older version: tick it, so a normal run fixes it.
     component_available cec && cec_repair && WANTED[cec]=1
+    # Steam Machine support from before 2.2.0 lacks the power-off fix.
+    component_available machine && machine_repair && WANTED[machine]=1
     # The terminal-only Steamify shortcut from before 2.0.1: tick it, so a
     # normal run replaces it with the app.
     launcher_repair && WANTED[launcher]=1
@@ -96,8 +98,8 @@ toggle_component() {
     if [[ "$c" == gaming && "${WANTED[gaming]}" == 0 ]]; then WANTED[single]=0; WANTED[boot]=0; fi
     # Where to boot to is part of the conversion, too.
     if [[ "$c" == boot && "${WANTED[boot]}" == 1 ]]; then WANTED[gaming]=1; fi
-    # The kernel pin is opt-out: ticked along with Steam Machine support.
-    if [[ "$c" == machine ]]; then WANTED[kpin]=${WANTED[machine]}; fi
+    # The kernel pin is opt-in (the power-off fix made it optional).
+    if [[ "$c" == machine && "${WANTED[machine]}" == 0 ]]; then WANTED[kpin]=0; fi
     if [[ "$c" == kpin && "${WANTED[kpin]}" == 1 ]]; then WANTED[machine]=1; fi
     # HDMI refresh boost and the BIOS update sit under Steam Machine support;
     # the boost also needs the pinned kernel (newer kernels don't need it).

lib/steam-machine.sh

@@ -1,6 +1,7 @@
 #!/bin/bash
 # "Steam Machine support" menu item, only on Valve Fremont hardware: the
-# front LED bar driver, LED access for Steam, and steamos-manager.
+# front LED bar driver, LED access for Steam, steamos-manager, and the
+# power-off fix (lib/fremont-poweroff.sh).
 # Sourced by steamify.sh; not meant to be run on its own.
 
 detect_valve_fremont() {
@@ -14,8 +15,8 @@ detect_valve_fremont() {
         [[ "$vendor" == "OEM" && "$product" == "F7F" ]]
 }
 
-# Kernel pinned on a Steam Machine: with newer linux-cachyos releases it
-# reboots instead of shutting down. The packages are kept in
+# Kernel pinned on a Steam Machine (optional): newer linux-cachyos releases
+# rebooted it instead of shutting down, which the power-off fix now handles. The packages are kept in
 # PINNED_KERNEL_DIR, so re-applying (or reinstalling after an update slipped
 # through) needs no download.
 PINNED_KERNEL_VER="7.1.6-1"
@@ -334,13 +335,13 @@ reload_powerdevil() {
 kernel_overview() {
     # Per installed kernel: headers (needed to build DKMS modules), the
     # in-kernel Steam controller driver, and, on a Steam Machine, whether the
-    # LED driver is built for it. Printed in the menu so it's easy to verify
+    # LED driver and the power-off fix are built for it. Printed in the menu so it's easy to verify
     # a kernel update or a newly added kernel got everything.
     local mark="${c_green}yes${c_reset}" miss="${c_red}no ${c_reset}" leds=false
     detect_valve_fremont && command -v dkms >/dev/null 2>&1 && leds=true
-    local kdir k pkg headers hid led running line
+    local kdir k pkg headers hid led off running line
     local legend="> = running; controller = Steam controller driver"
-    [[ "$leds" == true ]] && legend+=", LEDs = LED bar driver built"
+    [[ "$leds" == true ]] && legend+=", LEDs = LED bar driver built, power-off = power-off fix built"
     echo -e "  ${c_bold}Kernels${c_reset} ($legend)"
     for kdir in /usr/lib/modules/*/; do
         k="$(basename "$kdir")"
@@ -352,7 +353,8 @@ kernel_overview() {
         line="$(printf '%-23s %-18s headers %b  controller %b' "$k" "$pkg" "$headers" "$hid")"
         if [[ "$leds" == true ]]; then
             led="$miss"; dkms status -k "$k" leds-valve-dkms 2>/dev/null | grep -q installed && led="$mark"
-            line+="$(printf '  LEDs %b' "$led")"
+            off="$miss"; dkms status -k "$k" "$POWEROFF_DKMS_NAME" 2>/dev/null | grep -q installed && off="$mark"
+            line+="$(printf '  LEDs %b  power-off %b' "$led" "$off")"
         fi
         echo -e "  ${running}${line}"
     done
@@ -369,7 +371,13 @@ kernel_overview() {
 machine_available() { detect_valve_fremont; }
 
 machine_status() {
-    pacman -Qi leds-valve-dkms-git >/dev/null 2>&1 && pacman -Qi steamos-manager >/dev/null 2>&1
+    pacman -Qi leds-valve-dkms-git >/dev/null 2>&1 && pacman -Qi steamos-manager >/dev/null 2>&1 &&
+        poweroff_fix_installed
+}
+# Set up before 2.2.0: no power-off fix yet; the menu ticks it to add it.
+machine_repair() {
+    pacman -Qi leds-valve-dkms-git >/dev/null 2>&1 && pacman -Qi steamos-manager >/dev/null 2>&1 &&
+        ! poweroff_fix_installed
 }
 
 machine_enable() {
@@ -381,6 +389,8 @@ machine_enable() {
     ensure_aur_helper || { warn "Couldn't set up an AUR helper automatically. Install yay or paru, then run the wizard again."; return 1; }
     install_valve_led_driver || { warn "LED driver setup ran into a problem - see errors above."; return 1; }
     install_headers_boot_check
+    info "Installing the power-off fix (the machine stays off after shutting down)..."
+    poweroff_fix_enable || { err "Installing the power-off fix failed."; return 1; }
 
     # The LED files are root-only. Steam runs as the user; let it write them
     # in case it drives the bar directly (Valve's own privileged-write helper
@@ -424,6 +434,7 @@ machine_disable() {
     sudo udevadm control --reload
     sudo modprobe -r leds-valve 2>/dev/null
     sudo pacman -Rns --noconfirm leds-valve-dkms-git 2>/dev/null
+    poweroff_fix_disable
     krevert machine
     reload_powerdevil
     sudo systemctl disable ensure-kernel-headers.service 2>/dev/null