# DF-4553 VERDICT — not_reproduced (hardware absent); source-level: certain, one-token fix

## Root cause

`sv_suspend()` (sys/dev/sound/pci/vibes.c:644-659) saves each channel's
`dma_active` state and aborts it. Line 653 aborts the **playback** channel
`sc->pch` with `svrchan_trigger()` — the **record** channel's trigger —
a copy-paste of the line above it. `svrchan_trigger()`'s
`PCMTRIG_STOP`/`PCMTRIG_ABORT` arm (vibes.c:345-350) clears
`SV_RECORD_ENABLE` only; the playback enable (`SV_PLAY_ENABLE`,
`SV_REG_ENABLE` bit) is left set, so DMAA remains armed and
bus-mastering while the machine suspends. The record engine gets disabled
twice (harmless) and the playback engine not at all.

`sv_resume()` (vibes.c:661-687) later re-runs `svpchan_trigger(0, &sc->pch,
PCMTRIG_START)` only `if (sc->pch.dma_was_active)` — i.e. it papers over
the stale-enable state by reprogramming, but between suspend entry and
resume the device is in a state the driver does not model (continued DMA
into a buffer the sound framework considers quiesced; continued interrupt
generation feeding `chn_intr(sc->pch.channel)` while the pcm layer is
suspended).

## Why not reproduced here

The audit QEMU guest has no S3 SonicVibes (PCI 5333:ca00) device:
`pciconf -l | grep 5333` empty; with `snd_vibes.ko` loaded, `/dev/sndstat`
reports zero installed devices (see DF-4552 run.log). Suspend/resume of the
device therefore cannot be driven. No kernel-memory impact is claimed; the
finding is a device state-machine / PM defect with a one-token fix.

## Fix

vibes.c:653: `svrchan_trigger(NULL, &sc->pch, PCMTRIG_ABORT);` →
`svpchan_trigger(NULL, &sc->pch, PCMTRIG_ABORT);` (matches upstream
FreeBSD, whose snd_vibes uses the playback trigger for the playback
channel in sv_suspend). See fix.diff.

## Fix status (batch validation)
Applied with the 36 sibling fix.diffs of this batch in findings/poc/_batch41/all_fixes.patch; single in-guest `make -j6 nativekernel KERNCONF=X86_64_GENERIC` completed RC=0 with zero errors under -Werror (full log: findings/poc/_batch41/fix_build8.log). Behavior A/B intentionally skipped for this Info-tier item.