Fix duplicate dmix ipc_key collisions in asound.conf#1095
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All twelve loopback dmix devices shared ipc_key 1028. dmix instances with
the same ipc_key collide on one shared-memory segment, so opening a
loopback playback device intermittently fails with EINVAL ('unable to
open slave') depending on open order - the same signature as micro-nova#957. The
player then crash-loops; on our production unit the LMS player flapped
189 times/day until the keys were made unique. Also pins the 8ch dmixer
slave rate to 48000 so its format can't drift from the loopbacks.
Running in production on a stock 0.4.10 system since 2026-06-08 with
zero loopback open failures since.
Signed-off-by: Stamate Viorel <stamate.viorel@gmail.com>
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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What does this change intend to accomplish?
All twelve loopback dmix devices in
asound.confshareipc_key 1028. dmix instances with the same ipc_key collide on one shared-memory segment, so opening a loopback playback device intermittently fails withEINVAL/snd_pcm_dmix_open: unable to open slavedepending on open order and which zones are active. The player on that source then crash-loops: on our production unit the LMS player flapped 189 times/day until we made the keys unique. The log signature is identical to #957 (lb4c ... unable to open slave ... EINVAL), so I believe this is that issue's root cause. The patch gives every loopback dmix a unique ipc_key and pins the 8ch dmixer slave rate to 48000 so its format can't drift from the loopbacks.Running in production on a stock 0.4.10 unit since 2026-06-08 with zero loopback open failures since (previously several per day).
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