feat: on a supported NVIDIA card the SteamOS conversion replaces Gaming on NVIDIA

The conversion also sets up what Gaming on NVIDIA did there (kernel parameters, early modules, suspend memory, 32-bit libraries). Gaming on NVIDIA is only offered on older NVIDIA cards, or while it is on.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KkpbsMw4rQyBsxDG6ebHK2

lib/gamescope-nvidia.sh

@@ -61,12 +61,20 @@ gsn_env_disable() {
 gsn_enable() {
     # Only on a supported NVIDIA card; elsewhere the stock gamescope is right.
     nvidia_supported || return 0
+    # What NVIDIA's DRM stack wants (lib/nvidia.sh): modeset/fbdev on the kernel command line, the modules in the
+    # initramfs, video memory kept over suspend, the 32-bit libraries. Takes effect at the next boot, like the session.
+    nvidia_kernel_enable || return 1
+    nvidia_extras_enable || return 1
     gsn_install_package || return 1
     gsn_env_enable
     ok "gamescope draws NVIDIA's picture through GBM (gamescope_drm_gbm_scanout=1) from the next gaming mode start."
 }
 
 gsn_disable() {
-    # The setting goes; the patched package stays, like the other packages (steam, gamescope-session-cachyos).
+    # The setting goes, and what nvidia_*_enable added; the packages stay (patched gamescope, 32-bit libraries), like
+    # the other packages of the conversion (steam, gamescope-session-cachyos).
     gsn_env_disable
+    nvidia_supported || return 0
+    nvidia_extras_disable
+    nvidia_kernel_disable
 }

lib/menu.sh

@@ -206,8 +206,6 @@ detect_components() {
             component_available "$c" && component_selectable "$c" && ! is_action "$c" &&
                 [[ " ${NO_PRESELECT[*]} " != *" $c "* ]] && WANTED[$c]=1
         done
-        # On NVIDIA "Gaming on NVIDIA" is the default; the conversion (a patched gamescope, built here) is a choice.
-        nvidia_present && WANTED[gaming]=0 WANTED[glyphs]=0
         machine_available && WANTED[cec]=1
     fi
 }
@@ -286,8 +284,6 @@ defaults_list() {
         sel=false; component_selectable "$c" && sel=true
         on=false
         [[ "$sel" == true && " ${NO_PRESELECT[*]} " != *" $c "* ]] && on=true
-        # (On NVIDIA the conversion is a choice: "Gaming on NVIDIA" is preselected, see show_menu's first run.)
-        [[ "$c" == gaming || "$c" == glyphs ]] && nvidia_present && on=false
         [[ "$c" == cec ]] && machine_available && on=true
         items+="${items:+,}{\"id\":$(json_str "$c"),\"label\":$(json_str "${LABEL[$c]%%:*}")"
         items+=",\"hint\":$(json_str "$( [[ "${LABEL[$c]}" == *:* ]] && echo "${LABEL[$c]#*: }")")"

lib/nvidia.sh

@@ -37,9 +37,11 @@ nvidia_present() {
     return 1
 }
 
-# Shown on NVIDIA PCs. It and the SteamOS conversion exclude each other (both
-# would start Steam at login): the menu unticks one when the other is ticked.
-nvidia_available() { nvidia_present; }
+# The SteamOS conversion with the patched gamescope (lib/gamescope-nvidia.sh) replaces this on a supported card, so
+# this is for older NVIDIA cards, and for a PC where it is already on (so it can be turned off, or swapped for the
+# conversion). It and the conversion exclude each other (both would start Steam at login): the menu unticks one when
+# the other is ticked.
+nvidia_available() { nvidia_present && { ! nvidia_supported || nvidia_status; }; }
 bigpicture_available() { nvidia_available; }
 
 nvidia_status() {
@@ -76,14 +78,19 @@ nvidia_disable() {
     user_systemctl disable --now "$NVIDIA_UNIT" >/dev/null 2>&1
     rm -f "$unit"
     user_systemctl daemon-reload
-    nvidia_extras_disable
+    # Swapped for the SteamOS conversion (turned on first, in the same run): it needs the same settings, they stay.
+    gaming_status 2>/dev/null || nvidia_extras_disable
     pkgs="$(state_get nvidia installed_pkgs)"
+    if gaming_status 2>/dev/null; then
+        local p; pkgs=" $pkgs "
+        for p in $NVIDIA_LIB32_PKGS; do pkgs="${pkgs// $p / }"; done
+    fi
     # Only what Steamify installed; games and the Steam folder stay.
     # shellcheck disable=SC2086 # a list of package names
     [[ -n "$pkgs" ]] && sudo pacman -Rns --noconfirm $pkgs >/dev/null 2>&1
     state_clear nvidia
     krevert bigpicture
-    nvidia_kernel_disable
+    gaming_status 2>/dev/null || nvidia_kernel_disable
     ok "Steam no longer starts at login."
 }