Use the gmux backlight instead of the Touch Bar on T2 Macs (#6597)

* Match display backlight candidates against real globs [[ ]] does not do pathname expansion, so amdgpu_bl* and acpi_video* only ever tested for files with a literal asterisk in the name. Every machine without intel_backlight silently fell through to the alphabetical first entry, which picks acpi_video0 over amdgpu_bl0. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> * Use the gmux backlight instead of the Touch Bar on T2 Macs /sys/class/backlight on a T2 Mac holds appletb_backlight and gmux_backlight. Neither was a candidate, so the alphabetical fallback picked the Touch Bar and brightness keys dimmed it instead of the display. Add gmux_backlight and never fall back to the Touch Bar, which is not a display panel on any Mac. gmux ranks above the GPU backlights because apple-gmux only registers its device when the kernel has already selected it for the machine, and on dual-GPU Macs the GPU's own PWM stops driving the panel as soon as that GPU suspends. Fixes #6558 Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> --------- Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-08-07 23:59:50 +02:00
parent 0b24b844df
commit 007d6fcd7d
2 changed files with 74 additions and 4 deletions
@@ -0,0 +1,64 @@
+#!/bin/bash
+
+set -euo pipefail
+
+source "$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)/base-test.sh"
+
+tmp_dir=$(mktemp -d)
+trap 'rm -rf "$tmp_dir"' EXIT
+
+write_backlights() {
+  rm -rf "$tmp_dir/backlight"
+  mkdir -p "$tmp_dir/backlight"
+
+  local device
+  for device in "$@"; do
+    mkdir -p "$tmp_dir/backlight/$device"
+  done
+}
+
+hw_display() {
+  OMARCHY_BACKLIGHT_PATH="$tmp_dir/backlight" "$ROOT/bin/omarchy-hw-display"
+}
+
+write_backlights intel_backlight
+device=$(hw_display)
+[[ $device == "intel_backlight" ]] || fail "the only backlight is used" "actual: $device"
+pass "the only backlight is used"
+
+write_backlights acpi_video0 amdgpu_bl1
+device=$(hw_display)
+[[ $device == "amdgpu_bl1" ]] || fail "globbed candidates beat the alphabetical fallback" "actual: $device"
+pass "globbed candidates beat the alphabetical fallback"
+
+write_backlights acpi_video0 intel_backlight
+device=$(hw_display)
+[[ $device == "intel_backlight" ]] || fail "the candidate order is honored" "actual: $device"
+pass "the candidate order is honored"
+
+write_backlights nvidia_wmi_ec_backlight
+device=$(hw_display)
+[[ $device == "nvidia_wmi_ec_backlight" ]] || fail "an unknown backlight falls back to the first device" "actual: $device"
+pass "an unknown backlight falls back to the first device"
+
+write_backlights appletb_backlight gmux_backlight
+device=$(hw_display)
+[[ $device == "gmux_backlight" ]] || fail "a T2 Mac uses gmux instead of the Touch Bar" "actual: $device"
+pass "a T2 Mac uses gmux instead of the Touch Bar"
+
+write_backlights appletb_backlight
+if hw_display >/dev/null 2>&1; then
+  fail "the Touch Bar is never used as the display backlight"
+fi
+pass "the Touch Bar is never used as the display backlight"
+
+write_backlights acpi_video0 amdgpu_bl0 appletb_backlight gmux_backlight intel_backlight
+device=$(hw_display)
+[[ $device == "gmux_backlight" ]] || fail "gmux outranks the GPU backlights on dual-GPU Macs" "actual: $device"
+pass "gmux outranks the GPU backlights on dual-GPU Macs"
+
+write_backlights
+if hw_display >/dev/null 2>&1; then
+  fail "no backlight device reports failure"
+fi
+pass "no backlight device reports failure"