The Mute LED That Wouldn't Light: Chasing a Reddit Hack Into a Kernel Patch

Описание и применение

Проблема: индикатор мьют на ноутбуке HP Omen не включался. Решение: добавлен PCI‑квирк в драйвер Realtek ALC245, который автоматически управляет светодиодом при изменении состояния мьют. Патч прошёл в ядро и исправил аналогичную проблему на другом ноутбуке.

Задача

The mute LED on an HP Omen laptop did not light when the speakers were muted, despite the mute function working correctly.

Результат

A single PCI quirk table entry in the Linux kernel driver for Realtek ALC245 codecs restored mute LED functionality on HP laptops, eliminating the need for manual userspace hacks.

Рабочий процесс

• 1. Verify hardware works on Windows to rule out hardware failure.
• 2. Use evtest to confirm mute key events and audio muting.
• 3. Check /sys/class/leds for LED device – none found.
• 4. Identify codec via /proc/asound/card*/codec* (Realtek ALC245).
• 5. Locate relevant driver file (alc269.c) and search for SND_PCI_QUIRK entries.
• 6. Confirm LED control via hda-verb: coefficient 0x0b, values 0x7778 (on) and 0x7774 (off).
• 7. Test manual writes to verify LED control.
• 8. Choose correct quirk macro (V1) and add entry: SND_PCI_QUIRK(0x103c,0x8ba9,"HP Omen 16-wd0xxx",ALC245_FIXUP_HP_MUTE_LED_V1_COEFBIT).
• 9. Build kernel, reboot, verify LED works on mute.
• 10. Submit patch to kernel maintainers; patch applied.
• 11. Patch later used to fix similar issue on HP Victus laptop.
• 12. Document process and lessons learned.

Доказательства

The fix itself is simple and genuinely nothing to look at.

Источник

The maintainer Takashi Iwai applied it.

Источник