Fix duplicate dmix ipc_key collisions in asound.conf#1102
Closed
SteveMicroNova wants to merge 1 commit into
Closed
Fix duplicate dmix ipc_key collisions in asound.conf#1102SteveMicroNova wants to merge 1 commit into
SteveMicroNova wants to merge 1 commit into
Conversation
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 #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>
Contributor
Author
|
This may no longer be necessary as stamateviorel has just rebased their PR #1095, once tests are completed this is liable to be deleted |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
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).
Checklist
NOTE: This was originally pr #1095, I just screwed up the git history and didn't have the rights to fix it in that PR due to not owning the branch origin. Thank you to stamateviorel for this work!