marfrit
c7f6fb90cb
Removes the Phase 8.5 64 KiB frame-size cap by exporting CAPTURE
buffers as dmabuf-fds the daemon mmaps and writes pixels into
directly. Adds AV1 + H.264 codec support, V4L2 stateless control
registration, and the compliance polish that brings the driver
to 47/48 v4l2-compliance pass.
Protocol (include/daedalus_v4l2_proto.h):
- struct daedalus_req_decode grew capture-buffer metadata
(width/height/pix_fmt/num_planes + per-plane size+stride).
- New DAEDALUS_IOC_GET_DMABUF ioctl on the chardev: daemon
asks for a per-plane dmabuf fd, kernel calls vb2_core_expbuf
in daemon task context so the fd lands in the daemon's table.
Kernel m2m driver (kernel/daedalus_v4l2_main.c):
- Both queues switched to vb2_dma_contig_memops. OUTPUT was
vmalloc in 8.5; the switch is needed because vmalloc doesn't
honour V4L2_MEMORY_FLAG_NON_COHERENT and v4l2-compliance's
REQBUFS test rejected the driver because of it. We still
read bitstream via vb2_plane_vaddr (dma_contig gives a
kernel virtual address just like vmalloc did).
- dma_coerce_mask_and_coherent(DMA_BIT_MASK(32)) in probe.
- queue_setup populates alloc_devs[plane] = &pdev->dev for
both queues; allow_cache_hints=1 on both.
- daedalus_export_capture_dmabuf(cookie, plane, flags, *fd):
walks inflight list, calls vb2_core_expbuf on the CAPTURE
buffer in the caller's (daemon's) task context.
- device_run fills the new REQ_DECODE capture fields from
ctx->dst_fmt and maps ctx->src_fmt.pixelformat to
DAEDALUS_CODEC_VP9 / _AV1 / _H264 (was hard-wired to VP9).
- daedalus_complete_resp_frame handles both the 8.5 inline
path (kept for debugging) and the 8.6 dmabuf path (pixels
already in CAPTURE buffer, just set payload from metadata).
- enum_fmt advertises all 3 OUTPUT formats (VP9F, AV1F, S264).
- try_fmt preserves userspace colorspace fields instead of
overwriting with REC709 defaults (fixes 8.5 compliance fail).
- s_fmt propagates OUTPUT colorspace → CAPTURE (stateless
decoder round-trip test at v4l2-test-formats.cpp:958).
- 12 V4L2 stateless controls registered per open (VP9_FRAME,
VP9_COMPRESSED_HDR, H264_SPS/PPS/SCALING/PRED_WEIGHTS/
SLICE_PARAMS/DECODE_PARAMS, AV1_FRAME/SEQUENCE/
TILE_GROUP_ENTRY/FILM_GRAIN). Daemon ignores values (FFmpeg
re-parses); registration is what makes libva-v4l2-request
see us.
Kernel chardev (kernel/daedalus_v4l2_chardev.c):
- New unlocked_ioctl dispatching DAEDALUS_IOC_GET_DMABUF to
daedalus_export_capture_dmabuf.
- debugfs test_decode cookies unified with the m2m cookie
allocator via shared daedalus_next_cookie() — kills the
Phase 8.5 namespace collision.
Daemon (daemon/src/...):
- New dmabuf_capture.{c,h}: GET_DMABUF + mmap each plane on
REQ_DECODE; munmap + close on completion. O_RDWR | O_CLOEXEC
is essential — vb2_core_expbuf extracts O_ACCMODE from flags
and exports read-only by default (caught on first run; mmap
-EACCES on PROT_WRITE).
- decoder.{c,h}: lazily opens AV1 + H.264 AVCodecContexts in
addition to VP9 (dropped the -ENOSYS stubs). pack_nv12_to_planes
writes Y line-by-line into planes[0] with planes[0].stride;
interleaves Cb/Cr into planes[1] with planes[1].stride.
- chardev_client.c handle_req_decode: opens dmabuf planes,
runs decode (pixels land in CAPTURE buffer directly), closes
planes, sends metadata-only RESP_FRAME. No wire-pixel
allocation.
Test harness (tools/test_m2m_decode.c):
- Optional 5th arg `codec` (vp9 | av1 | h264). Same client
drives all three codecs.
Verification on hertz (Pi 5, 6.12.75+rpt-rpi-2712):
Bit-exact end-to-end vs `ffmpeg -pix_fmt nv12`:
VP9 1920x1080 3,110,400 bytes MATCH
AV1 128x96 18,432 bytes MATCH
H.264 128x96 18,432 bytes MATCH
VP9 1080p went through the full dmabuf path with no chardev
payload bloat — the same chardev that capped at 64 KiB in 8.5
now ferries metadata only and lets the daemon mmap+write a
3.1 MB frame directly into the V4L2 client's buffer.
v4l2-compliance:
Phase 8.1: 44/48
Phase 8.5: 44/48 (different fails after m2m landed)
Phase 8.6: 47/48
Only remaining: VIDIOC_(TRY_)DECODER_CMD (needs media
controller — explicitly Phase 8.7 work).
11 standard compound controls visible:
vp9_frame_decode_parameters, vp9_probabilities_updates,
h264_sequence_parameter_set, h264_picture_parameter_set,
h264_scaling_matrix, h264_prediction_weight_table,
h264_slice_parameters, h264_decode_parameters,
av1_sequence_parameters, av1_frame_parameters,
av1_film_grain (av1_tile_group_entry refused by hdl->error
on this kernel — skipped silently).
Clean SIGTERM + rmmod, no oops/WARN.
Roadmap update (docs/roadmap.md):
- Phase 8.6 marked closed with the closure-doc reference.
- Phase 8.7 reshaped to (1) media controller, (2) perf +
daedalus_dispatch_* substitution, (3) HDR/10-bit, (4)
long-form multi-frame streaming.
Per correctness-before-speed:
- Real V4L2 dmabuf via vb2_core_expbuf (not a sideband
fd-passing hack).
- O_RDWR access mode threaded through correctly.
- Strict pixel-byte comparison against ffmpeg, not "looks
right" eyeballing.
- Each compliance edge documented with the underlying test
source-line + the fix.
- All resource paths cleaned (munmap + close per plane on
every exit, including error paths).
Phase 8.7 next: media controller binding (closes last
compliance fail), per-frame profiling, QPU dispatch
substitution targeting 30fps@1080p from
30fps-floor-is-fine memory.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
105 lines
3.8 KiB
C
105 lines
3.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
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/*
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* daedalus-v4l2 — kernel-internal device/state declarations.
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*
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* Shared between daedalus_v4l2_main.c (V4L2 m2m driver) and
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* daedalus_v4l2_chardev.c (kernel↔daemon bridge). The chardev
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* needs to look up in-flight V4L2 requests by cookie to complete
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* the m2m job when RESP_FRAME arrives — that path lives in
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* daedalus_complete_resp_frame().
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*/
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#ifndef DAEDALUS_V4L2_MAIN_H
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#define DAEDALUS_V4L2_MAIN_H
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#include <linux/list.h>
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#include <linux/mutex.h>
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#include <linux/platform_device.h>
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#include <media/v4l2-device.h>
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#include <media/v4l2-dev.h>
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#include <media/v4l2-mem2mem.h>
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#include "daedalus_v4l2_proto.h"
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/**
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* struct daedalus_dev - top-level device state (singleton for now)
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* @pdev: owning platform device (synthesised in module_init)
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* @v4l2_dev: V4L2 device parent for any video_device we register
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* @vdev: video_device exposed as /dev/videoNN
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* @m2m_dev: mem2mem device shared by all per-open contexts
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* @m2m_lock: serialises vb2 queue + v4l2 ioctl ops
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* @inflight: list of struct daedalus_inflight (REQ_DECODE sent,
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* RESP_FRAME not yet returned)
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* @inflight_lock: protects @inflight
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*
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* Singleton per-module instance. Multi-instance support (one
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* decoder per /dev/videoNN) would require breaking g_daedalus_dev
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* out of daedalus_v4l2_main.c; not needed yet.
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*/
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struct daedalus_dev {
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struct platform_device *pdev;
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struct v4l2_device v4l2_dev;
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struct video_device vdev;
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struct v4l2_m2m_dev *m2m_dev;
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struct mutex m2m_lock;
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struct list_head inflight;
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struct mutex inflight_lock;
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};
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/* Module-wide singleton accessor (chardev needs this for RESP_FRAME). */
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struct daedalus_dev *daedalus_get_dev(void);
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/**
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* daedalus_next_cookie() - shared cookie allocator
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*
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* Returns the next monotonically increasing request cookie.
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* Used by both the V4L2 m2m device_run path (for REQ_DECODE
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* from real OUTPUT buffers) and the chardev debugfs
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* test_decode path (for hand-crafted REQ_DECODE injection),
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* so the two namespaces never collide and RESP_FRAME logs
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* stay deterministic.
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*/
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u32 daedalus_next_cookie(void);
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/**
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* daedalus_complete_resp_frame() - chardev RESP_FRAME completion
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* @cookie: cookie carried by the matching REQ_DECODE
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* @fr: RESP_FRAME header from the daemon
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* @pixels: inline pixel bytes following the header in the
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* chardev payload (may be NULL if @pixels_len == 0)
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* @pixels_len: number of inline pixel bytes
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*
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* Called from the chardev write() path on RESP_FRAME. Looks up
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* the in-flight request, copies inline pixel data into the
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* CAPTURE vb2 buffer if available (Phase 8.5 path; Phase 8.6
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* skips the copy because the daemon decoded directly into the
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* dmabuf), then completes both src+dst buffers and finishes
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* the m2m job. Silently drops responses for unknown cookies
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* (pr_warn_ratelimited).
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*/
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void daedalus_complete_resp_frame(u32 cookie,
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const struct daedalus_resp_frame *fr,
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const u8 *pixels, size_t pixels_len);
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/**
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* daedalus_export_capture_dmabuf() - chardev GET_DMABUF backend
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* @cookie: cookie from the matching REQ_DECODE
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* @plane: plane index (0-based) within the CAPTURE buffer
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* @flags: flags for dma_buf_fd (O_CLOEXEC etc.)
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* @out_fd: out: installed dmabuf fd in the calling task's
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* fd table (only valid when return value == 0)
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*
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* Called from the chardev DAEDALUS_IOC_GET_DMABUF ioctl
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* handler. Looks up the in-flight V4L2 request by cookie,
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* exports the CAPTURE vb2 buffer's plane as a dma_buf via
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* vb2_core_expbuf in the daemon's task context. Caller must
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* NOT touch out_fd on non-zero return.
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*
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* Return: 0 on success, -EINVAL for unknown cookie or bad
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* plane, propagated -errno from vb2_core_expbuf otherwise.
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*/
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int daedalus_export_capture_dmabuf(u32 cookie, u32 plane, u32 flags,
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int *out_fd);
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#endif /* DAEDALUS_V4L2_MAIN_H */
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