Le 02/10/2023 à 15:37, Hans Verkuil a écrit :
On 27/09/2023 17:35, Benjamin Gaignard wrote:Use one of the struct v4l2_create_buffers reserved bytes to report the maximum possible number of buffers for the queue. V4l2 framework set V4L2_BUF_CAP_SUPPORTS_SET_MAX_BUFS flags in queue capabilities so userland can know when the field is valid. Signed-off-by: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxxxxx> --- .../userspace-api/media/v4l/vidioc-create-bufs.rst | 8 ++++++-- Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst | 1 + drivers/media/common/videobuf2/videobuf2-v4l2.c | 9 +++++++-- drivers/media/v4l2-core/v4l2-ioctl.c | 4 ++-- include/uapi/linux/videodev2.h | 7 ++++++- 5 files changed, 22 insertions(+), 7 deletions(-) diff --git a/Documentation/userspace-api/media/v4l/vidioc-create-bufs.rst b/Documentation/userspace-api/media/v4l/vidioc-create-bufs.rst index a048a9f6b7b6..1a46549e7462 100644 --- a/Documentation/userspace-api/media/v4l/vidioc-create-bufs.rst +++ b/Documentation/userspace-api/media/v4l/vidioc-create-bufs.rst @@ -116,9 +116,13 @@ than the number requested. - ``flags`` - Specifies additional buffer management attributes. See :ref:`memory-flags`. - * - __u32 - - ``reserved``\ [6] + - ``max_buffers`` + - If V4L2_BUF_CAP_SUPPORTS_SET_MAX_BUFS capability flag is set + this field indicate the maximum possible number of buffers + for this queue. + * - __u32 + - ``reserved``\ [5] - A place holder for future extensions. Drivers and applications must set the array to zero.diff --git a/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst b/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rstindex 099fa6695167..0395187e1a5a 100644 --- a/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst +++ b/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst @@ -120,6 +120,7 @@ aborting or finishing any DMA in progress, an implicit .. _V4L2-BUF-CAP-SUPPORTS-ORPHANED-BUFS: .. _V4L2-BUF-CAP-SUPPORTS-M2M-HOLD-CAPTURE-BUF: .. _V4L2-BUF-CAP-SUPPORTS-MMAP-CACHE-HINTS: +.. _V4L2-BUF-CAP-SUPPORTS-SET-MAX-BUFS:.. raw:: latex diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.cindex 278ea1107b01..655133f1ae2b 100644 --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c @@ -686,6 +686,7 @@ EXPORT_SYMBOL(vb2_querybuf); static void fill_buf_caps(struct vb2_queue *q, u32 *caps) { *caps = V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS; + *caps |= V4L2_BUF_CAP_SUPPORTS_SET_MAX_BUFS; if (q->io_modes & VB2_MMAP) *caps |= V4L2_BUF_CAP_SUPPORTS_MMAP; if (q->io_modes & VB2_USERPTR) @@ -767,9 +768,13 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)fill_buf_caps(q, &create->capabilities);validate_memory_flags(q, create->memory, &create->flags); - create->index = q->num_buffers; - if (create->count == 0) + + create->max_buffers = q->max_num_buffers; + + if (create->count == 0) { + create->index = vb2_get_num_buffers(q);This breaks git bisect: this function isn't introduced until patch 21/53. Note: with the build scripts you can just run it with: ./build.sh -patches 53 ... and it will apply each patch in sequence and attempt to compile it.
It should be create->index = q->num_buffers; The error is also in v9...
Regards, Hansreturn ret != -EBUSY ? ret : 0; + }switch (f->type) {case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE: diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c index f4d9d6279094..700db197e371 100644 --- a/drivers/media/v4l2-core/v4l2-ioctl.c +++ b/drivers/media/v4l2-core/v4l2-ioctl.c @@ -483,9 +483,9 @@ static void v4l_print_create_buffers(const void *arg, bool write_only) { const struct v4l2_create_buffers *p = arg;- pr_cont("index=%d, count=%d, memory=%s, capabilities=0x%08x, ",+ pr_cont("index=%d, count=%d, memory=%s, capabilities=0x%08x, max buffers=%u", p->index, p->count, prt_names(p->memory, v4l2_memory_names), - p->capabilities); + p->capabilities, p->max_buffers); v4l_print_format(&p->format, write_only); }diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.hindex 78260e5d9985..b0dbb1be728c 100644 --- a/include/uapi/linux/videodev2.h +++ b/include/uapi/linux/videodev2.h @@ -1034,6 +1034,7 @@ struct v4l2_requestbuffers { #define V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS (1 << 4) #define V4L2_BUF_CAP_SUPPORTS_M2M_HOLD_CAPTURE_BUF (1 << 5) #define V4L2_BUF_CAP_SUPPORTS_MMAP_CACHE_HINTS (1 << 6) +#define V4L2_BUF_CAP_SUPPORTS_SET_MAX_BUFS (1 << 7)/*** struct v4l2_plane - plane info for multi-planar buffers @@ -2604,6 +2605,9 @@ struct v4l2_dbg_chip_info { * @flags: additional buffer management attributes (ignored unless the * queue has V4L2_BUF_CAP_SUPPORTS_MMAP_CACHE_HINTS capability * and configured for MMAP streaming I/O). + * @max_buffers: if V4L2_BUF_CAP_SUPPORTS_SET_MAX_BUFS capability flag is set + * this field indicate the maximum possible number of buffers + * for this queue. * @reserved: future extensions */ struct v4l2_create_buffers { @@ -2613,7 +2617,8 @@ struct v4l2_create_buffers { struct v4l2_format format; __u32 capabilities; __u32 flags; - __u32 reserved[6]; + __u32 max_buffers; + __u32 reserved[5]; };/*
