2 Commits

Author	SHA1	Message	Date
enricobuehler	92c6da9546	fix(capture/mutter): restore zero-copy + sync via dmabuf implicit fence ... The previous attempt (8531135) dropped zero-copy on Mutter+NVIDIA for a sticky CPU/SHM fallback that (a) still listed SPA_DATA_DmaBuf in its buffer types, so Mutter kept handing dmabufs that got mmap-read UNsynced — making the flashing worse, not better — and (b) hinged on producer explicit sync, which Mutter+NVIDIA cannot do (`error alloc buffers` / no cogl sync_fd, confirmed in worker-3 logs). Revert the capture restructure to the original zero-copy dmabuf path, and fix the NVIDIA stale-frame race the RIGHT way for a producer that can't do explicit sync: the consumer snapshots the dmabuf's implicit fence (DMA_BUF_IOCTL_EXPORT_SYNC_FILE) and waits the producer's render before sampling (new dmabuf_fence module, ioctl number unit-tested). Covers the GPU import and the CPU mmap read. Logs once whether a render was actually in flight (waited=true → the driver fences and the race is closed; false → no implicit fence, so we learn zero-copy still needs SHM here). drm_sync (the explicit-sync primitive) is kept and verified but marked unused — no targeted compositor produces a usable sync_fd today; ready to wire in when one does. The Bug-2 input fix (held-key release on disconnect) from 8531135 is kept. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>	2026-06-13 09:28:17 +00:00
enricobuehler	8531135bb7	fix(capture/mutter): stale-frame flashes + stuck input after disconnect on GNOME ... Deep dive into the two GNOME-only host bugs (KWin/gamescope clean): 1. Stale-frame flashes (windows at old positions, typed text reverting): Mutter renders its virtual monitors DIRECTLY into the PipeWire buffer pool, and NVIDIA has no implicit dmabuf fencing — our zero-copy import raced the render and encoded each pool buffer's PREVIOUS contents. Fix, in order of preference: - Consumer-side PipeWire explicit sync (SPA_META_SyncTimeline): new drm_sync module (DRM timeline-syncobj wait/signal via raw ioctls, unit-tested incl. a live signal->wait round trip); announced post-format via update_params (the OBS pattern — at connect time the meta makes producers fail allocation, observed on KWin), with a blocks=3 Buffers filter so the producer's sync pod wins; acquire point awaited before any read (GPU import or CPU mmap), release point signaled on every path. - Where the producer can't do explicit sync (Mutter on NVIDIA today: no cogl sync_fd, "error alloc buffers"), a sticky fallback flips the capture to the synchronous CPU/shm path — Mutter's glReadPixels download orders against its render, so frames are correct by construction. First session pays one ~10 s probe+retry; later sessions go straight there. Validated live on home-worker-3 (GNOME 50 + RTX 4090): clean fallback, 30 MB HEVC streamed. - Sync is only announced on Mutter sessions (new VirtualOutput.mutter tag): KWin+NVIDIA fails allocation when merely asked, and doesn't need it (verified unchanged: zero-copy CUDA import + 1.1 MB/10 s). PUNKTFUNK_EXPLICIT_SYNC=0 disables the probe outright. 2. Clicks wedged in the focused app after disconnect+reconnect: a client vanishing mid-press left keys/buttons latched in the compositor — Mutter keeps the destroyed EIS device's implicit grab and the focused app stops taking clicks until restarted. EiState now tracks held keys/buttons/touches (wire codes) and synthesizes releases through the normal inject path before the EIS connection goes away. GNOME hosts on NVIDIA temporarily lose zero-copy (correctness over throughput); the moment Mutter+driver gain working explicit sync, the sync path engages automatically and zero-copy returns. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>	2026-06-13 00:34:42 +00:00