From: Kirill A. Korinsky Subject: Re: sys/uvideo: don't skip frame immediately when buffer unavailable (regression from v1.256) To: marcus@nazgul.ch, tech@openbsd.org, ian@darwinsys.com Date: Thu, 17 Apr 2025 10:00:55 +0200 Markus, Ian, here a future improvment of this diff, this time I stricly requires that mmap buffer is switched or "grab" only for the first sample of the frame. I can't reproduce glitches on my motion test case. May I ask you to try this one? Index: sys/dev/usb/uvideo.c =================================================================== RCS file: /home/cvs/src/sys/dev/usb/uvideo.c,v diff -u -p -r1.257 uvideo.c --- sys/dev/usb/uvideo.c 6 Apr 2025 09:46:30 -0000 1.257 +++ sys/dev/usb/uvideo.c 17 Apr 2025 08:00:03 -0000 @@ -66,6 +66,7 @@ struct uvideo_softc { struct uvideo_frame_buffer sc_frame_buffer; struct uvideo_mmap sc_mmap[UVIDEO_MAX_BUFFERS]; + struct uvideo_mmap *sc_mmap_cur; uint8_t *sc_mmap_buffer; size_t sc_mmap_buffer_size; int sc_mmap_buffer_idx; @@ -170,8 +171,8 @@ void uvideo_vs_decode_stream_header(str uint8_t *, int); void uvideo_vs_decode_stream_header_isight(struct uvideo_softc *, uint8_t *, int); -int uvideo_get_buf(struct uvideo_softc *); -void uvideo_mmap_queue(struct uvideo_softc *, uint8_t *, int, int); +uint8_t * uvideo_mmap_getbuf(struct uvideo_softc *); +void uvideo_mmap_queue(struct uvideo_softc *, int, int); void uvideo_read(struct uvideo_softc *, uint8_t *, int); usbd_status uvideo_usb_control(struct uvideo_softc *, uint8_t, uint8_t, uint16_t, uint8_t *, size_t); @@ -2333,6 +2334,7 @@ uvideo_vs_decode_stream_header(struct uv struct uvideo_frame_buffer *fb = &sc->sc_frame_buffer; struct usb_video_stream_header *sh; int sample_len; + uint8_t *buf; if (frame_size < UVIDEO_SH_MIN_LEN) /* frame too small to contain a valid stream header */ @@ -2364,16 +2366,17 @@ uvideo_vs_decode_stream_header(struct uv fb->fid = sh->bFlags & UVIDEO_SH_FLAG_FID; fb->offset = 0; fb->error = 0; + } else if (fb->fid != (sh->bFlags & UVIDEO_SH_FLAG_FID)) { + /* first sample for a frame, due to flip FID */ + DPRINTF(1, "%s: %s: wrong FID, ignore last frame!\n", + DEVNAME(sc), __func__); + fb->sample = 1; + fb->fid = sh->bFlags & UVIDEO_SH_FLAG_FID; + fb->offset = 0; + fb->error = 0; } else { - /* continues sample for a frame, check consistency */ - if (fb->fid != (sh->bFlags & UVIDEO_SH_FLAG_FID)) { - DPRINTF(1, "%s: %s: wrong FID, ignore last frame!\n", - DEVNAME(sc), __func__); - fb->sample = 1; - fb->fid = sh->bFlags & UVIDEO_SH_FLAG_FID; - fb->offset = 0; - fb->error = 0; - } + /* continues sample for a frame */ + fb->sample++; } if (sh->bFlags & UVIDEO_SH_FLAG_ERR) { @@ -2382,6 +2385,11 @@ uvideo_vs_decode_stream_header(struct uv fb->error = 1; } + if (sc->sc_mmap_flag) + buf = uvideo_mmap_getbuf(sc); + else + buf = sc->sc_frame_buffer.buf; + /* save sample */ sample_len = frame_size - sh->bLength; if (sample_len > fb->buf_size - fb->offset) { @@ -2390,8 +2398,8 @@ uvideo_vs_decode_stream_header(struct uv sample_len = fb->buf_size - fb->offset; fb->error = 1; } - if (sample_len > 0) { - bcopy(frame + sh->bLength, fb->buf + fb->offset, sample_len); + if (buf && sample_len > 0) { + bcopy(frame + sh->bLength, buf + fb->offset, sample_len); fb->offset += sample_len; } @@ -2409,7 +2417,7 @@ uvideo_vs_decode_stream_header(struct uv if (sc->sc_mmap_flag) { /* mmap */ - uvideo_mmap_queue(sc, fb->buf, fb->offset, fb->error); + uvideo_mmap_queue(sc, fb->offset, fb->error); } else if (fb->error) { DPRINTF(1, "%s: %s: error frame, skipped!\n", DEVNAME(sc), __func__); @@ -2446,6 +2454,7 @@ uvideo_vs_decode_stream_header_isight(st { struct uvideo_frame_buffer *fb = &sc->sc_frame_buffer; int sample_len, header = 0; + uint8_t *buf; uint8_t magic[] = { 0x11, 0x22, 0x33, 0x44, 0xde, 0xad, 0xbe, 0xef, 0xde, 0xad, 0xfa, 0xce }; @@ -2463,27 +2472,52 @@ uvideo_vs_decode_stream_header_isight(st if (header) { if (sc->sc_mmap_flag) { /* mmap */ - uvideo_mmap_queue(sc, fb->buf, fb->offset, 0); + uvideo_mmap_queue(sc, fb->offset, 0); } else { /* read */ uvideo_read(sc, fb->buf, fb->offset); } fb->offset = 0; } else { + if (sc->sc_mmap_flag) + buf = uvideo_mmap_getbuf(sc); + else + buf = sc->sc_frame_buffer.buf; + + if (buf == NULL) + return; + /* save sample */ sample_len = frame_size; if ((fb->offset + sample_len) <= fb->buf_size) { - bcopy(frame, fb->buf + fb->offset, sample_len); + bcopy(frame, buf + fb->offset, sample_len); fb->offset += sample_len; } } } -int -uvideo_get_buf(struct uvideo_softc *sc) +uint8_t * +uvideo_mmap_getbuf(struct uvideo_softc *sc) { int i, idx = sc->sc_mmap_buffer_idx; + /* + * Section 2.4.3.2 explicitly allows multiple frames per one + * transfer and multiple transfers per one frame. + */ + if (sc->sc_mmap_cur != NULL) + return sc->sc_mmap_cur->buf; + + /* use the next buffer only for the first frame's sample */ + if (sc->sc_frame_buffer.sample > 1) { + DPRINTF(1, "%s: %s: not the first sample: %d\n", + DEVNAME(sc), __func__, sc->sc_frame_buffer.sample); + return NULL; + } + + if (sc->sc_mmap_count == 0 || sc->sc_mmap_buffer == NULL) + panic("%s: mmap buffers not allocated", __func__); + /* find a buffer which is ready for queueing */ for (i = 0; i < sc->sc_mmap_count; i++) { if (sc->sc_mmap[sc->sc_mmap_buffer_idx].v4l2_buf.flags & @@ -2497,51 +2531,45 @@ uvideo_get_buf(struct uvideo_softc *sc) sc->sc_mmap_buffer_idx = 0; } - if (i == sc->sc_mmap_count) - return -1; + if (i == sc->sc_mmap_count) { + DPRINTF(1, "%s: %s: mmap queue is full!\n", + DEVNAME(sc), __func__); + return NULL; + } + + sc->sc_mmap_cur = &sc->sc_mmap[idx]; - return idx; + return sc->sc_mmap_cur->buf; } void -uvideo_mmap_queue(struct uvideo_softc *sc, uint8_t *buf, int len, int err) +uvideo_mmap_queue(struct uvideo_softc *sc, int len, int err) { - int i; - - if (sc->sc_mmap_count == 0 || sc->sc_mmap_buffer == NULL) - panic("%s: mmap buffers not allocated", __func__); - - /* find a buffer which is ready for queueing */ - i = uvideo_get_buf(sc); - if (i == -1) { - DPRINTF(1, "%s: %s: mmap queue is full!\n", - DEVNAME(sc), __func__); + if (sc->sc_mmap_cur == NULL) return; - } - /* copy frame to mmap buffer and report length */ - bcopy(buf, sc->sc_mmap[i].buf, len); - sc->sc_mmap[i].v4l2_buf.bytesused = len; + /* report frame length */ + sc->sc_mmap_cur->v4l2_buf.bytesused = len; /* timestamp it */ - getmicrouptime(&sc->sc_mmap[i].v4l2_buf.timestamp); - sc->sc_mmap[i].v4l2_buf.flags &= ~V4L2_BUF_FLAG_TIMESTAMP_MASK; - sc->sc_mmap[i].v4l2_buf.flags |= V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC; - sc->sc_mmap[i].v4l2_buf.flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK; - sc->sc_mmap[i].v4l2_buf.flags |= V4L2_BUF_FLAG_TSTAMP_SRC_EOF; - sc->sc_mmap[i].v4l2_buf.flags &= ~V4L2_BUF_FLAG_TIMECODE; + getmicrouptime(&sc->sc_mmap_cur->v4l2_buf.timestamp); + sc->sc_mmap_cur->v4l2_buf.flags &= ~V4L2_BUF_FLAG_TIMESTAMP_MASK; + sc->sc_mmap_cur->v4l2_buf.flags |= V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC; + sc->sc_mmap_cur->v4l2_buf.flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK; + sc->sc_mmap_cur->v4l2_buf.flags |= V4L2_BUF_FLAG_TSTAMP_SRC_EOF; + sc->sc_mmap_cur->v4l2_buf.flags &= ~V4L2_BUF_FLAG_TIMECODE; /* forward error bit */ - sc->sc_mmap[i].v4l2_buf.flags &= ~V4L2_BUF_FLAG_ERROR; + sc->sc_mmap_cur->v4l2_buf.flags &= ~V4L2_BUF_FLAG_ERROR; if (err) - sc->sc_mmap[i].v4l2_buf.flags |= V4L2_BUF_FLAG_ERROR; + sc->sc_mmap_cur->v4l2_buf.flags |= V4L2_BUF_FLAG_ERROR; /* queue it */ - sc->sc_mmap[i].v4l2_buf.flags |= V4L2_BUF_FLAG_DONE; - sc->sc_mmap[i].v4l2_buf.flags &= ~V4L2_BUF_FLAG_QUEUED; - SIMPLEQ_INSERT_TAIL(&sc->sc_mmap_q, &sc->sc_mmap[i], q_frames); - DPRINTF(2, "%s: %s: frame queued on index %d\n", - DEVNAME(sc), __func__, i); + sc->sc_mmap_cur->v4l2_buf.flags |= V4L2_BUF_FLAG_DONE; + sc->sc_mmap_cur->v4l2_buf.flags &= ~V4L2_BUF_FLAG_QUEUED; + SIMPLEQ_INSERT_TAIL(&sc->sc_mmap_q, sc->sc_mmap_cur, q_frames); + sc->sc_mmap_cur = NULL; + DPRINTF(2, "%s: %s: frame queued\n", DEVNAME(sc), __func__); wakeup(sc); @@ -3507,6 +3535,7 @@ uvideo_reqbufs(void *v, struct v4l2_requ } sc->sc_mmap_buffer_idx = 0; + sc->sc_mmap_cur = NULL; /* tell how many buffers we have really allocated */ rb->count = sc->sc_mmap_count;