Public bug reported:
Summary
On the Acer Chromebook Spin 311 (board codename Juniper, MediaTek
MT8183, ARM64), the internal speaker is completely silent on every boot.
ALSA playback fails with -EIO: the AFE (Audio Front End) DMA engine's
current-position register never advances and its period-elapsed
interrupt never fires, while ordinary register reads/writes over APB
keep working normally. Register-level debugging shows this is a classic
"AXI bus protection never cleared" symptom.
Root cause
Upstream commit 0e789b491ba0 ("pmdomain: core: Leave powered-on genpds
on until sync_state") changed genpd to trust that a power domain already
reported "on" at probe time is fully initialized, skipping the real
power-off/power-on sequencing that normally clears AXI bus protection
for that domain. On Juniper, the firmware leaves the audio power domain
in exactly this misleading "on but not really initialized" state, so
this hardware sequencing never runs and the speaker never produces
sound.
This is the same class of bug already fixed for the MFG/GPU domains in
commit 818d56ac1d ("pmdomain: mediatek: Fix mt8183 hang on boot"), which
never covered the audio domain.
Confirmed via
A full git bisect across released kernel versions (v6.6 through v7.0)
run on the real hardware at every step: audio works on v6.6, breaks
starting at the version containing 0e789b491ba0.
Fix
One-line fix: add .caps = MTK_SCPD_KEEP_DEFAULT_OFF to the
MT8183_POWER_DOMAIN_AUDIO entry in drivers/pmdomain/mediatek/mt8183-pm-
domains.h -- the same pattern already applied to the MFG domains.
Verified fixing audio playback on real hardware. Patch attached.
Submitted upstream to the pmdomain/MediaTek maintainers and relevant mailing
lists (linux-pm, linux-kernel, linux-arm-kernel, linux-mediatek) on 2026-10-05.
Message-ID: [email protected]
(should appear at
https://lore.kernel.org/all/[email protected]/ once the
list archives index it)
Requesting: this one-line, already-upstream-submitted fix be backported
into Ubuntu's kernel ahead of the next full upstream rebase, since it's
a narrowly-scoped regression fix with no risk to other boards/domains.
Affected package / version
- Package: linux (Ubuntu 26.04 "resolute")
- Kernel version where bug reproduces: 7.0 (and later, back through whichever
release first picked up 0e789b491ba0)
- Hardware: Acer Chromebook Spin 311 (CP311-3H), board Juniper (kukui/jacuzzi
family), MediaTek MT8183
System info
$ uname -a
Linux juniper-ubuntu 7.0.14 #6 SMP PREEMPT Mon Oct 5 12:16:54 UTC 2026 aarch64
GNU/Linux
$ lsb_release -a
Distributor ID: Ubuntu
Description: Ubuntu 26.04 LTS
Release: 26.04
Codename: resolute
$ cat /sys/firmware/devicetree/base/model
Google juniper sku16 board
$ aplay -l
card 0: mt8183mt6358ts3 [mt8183_mt6358_ts3a227_max98357], device 0: Playback_1
(*) []
card 0: mt8183mt6358ts3 [mt8183_mt6358_ts3a227_max98357], device 1: Playback_2
(*) []
card 0: mt8183mt6358ts3 [mt8183_mt6358_ts3a227_max98357], device 2: Playback_3
(*) []
card 0: mt8183mt6358ts3 [mt8183_mt6358_ts3a227_max98357], device 7:
Playback_HDMI (*) []
dmesg evidence of the firmware quirk
This is the root trigger condition this bug/patch addresses -- genpd
detecting (and, with the fix applied, correctly forcing off then back
on) a power domain the firmware left in a misleading "on" state at boot:
[ 0.815485] mtk-power-controller 10006000.syscon:power-controller:
/soc/syscon@10006000/power-controller/power-domain@0: A default off power
domain has been ON
[ 0.815577] infra_audio_26m_bclk already disabled
[ 0.815986] infra_audio already disabled
[ 0.816635] infra_audio_26m_bclk already unprepared
[ 0.816942] infra_audio already unprepared
(Captured on the patched kernel, where this message is expected/harmless
-- genpd correctly recovers. On an unpatched kernel, genpd trusts the
misleading "on" state instead of recovering from it, and this is where
silent audio results.)
** Affects: linux (Ubuntu)
Importance: Undecided
Status: New
** Tags: arm64 audio chromebook mediatek regression
** Patch added: "Upstream patch (already submitted to pmdomain/MediaTek
maintainers)"
https://bugs.launchpad.net/bugs/2169591/+attachment/6005928/+files/0001-pmdomain-mediatek-mt8183-fix-silent-audio-from-premature-sync_state.patch
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https://bugs.launchpad.net/bugs/2169591
Title:
Internal speaker silent on Acer Chromebook Spin 311 (MT8183/Juniper) —
audio power domain left unpowered by premature genpd sync_state
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