| Message ID | 20231017144756.34719-45-benjamin.gaignard@collabora.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add DELETE_BUF ioctl | expand |
On 17/10/2023 16:47, 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@collabora.com> > --- > .../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 | 2 ++ > drivers/media/v4l2-core/v4l2-ioctl.c | 4 ++-- > include/uapi/linux/videodev2.h | 7 ++++++- > 5 files changed, 17 insertions(+), 5 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..380195c2a00a 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_num_buffers`` > + - If V4L2_BUF_CAP_SUPPORTS_MAX_NUM_BUFFERS capability flag is set If -> If the > + this field indicate the maximum possible number of buffers indicate -> indicates > + 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.rst > index 099fa6695167..0b3a41a45d05 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-MAX-NUM-BUFFERS: > > .. raw:: latex > > diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c > index f3cf4b235c1f..201438ffd13f 100644 > --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c > +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c > @@ -680,6 +680,7 @@ 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_MAX_NUM_BUFFERS; Hmm. This flag is set for both VIDIOC_REQBUFS and _CREATE_BUFS, but the max_num_buffers field is only reported through VIDIOC_CREATE_BUFS. I think this flag should be set in vb2_create_bufs() only. Alternatively, we add a max_num_buffers field to struct v4l2_requestbuffers as well: struct v4l2_requestbuffers { __u32 count; __u32 type; /* enum v4l2_buf_type */ __u32 memory; /* enum v4l2_memory */ __u32 capabilities; __u8 flags; __u8 reserved[1]; __u16 max_num_buffers; }; Since 32768 is the max for max_num_buffers, this will fit in a u16. I'm not sure it is worth the effort, though. How likely is it that there is a driver supporting more than 32 buffers, yet does not support CREATE_BUFS? So for now, I think it is best to just set this BUF_CAP flag in vb2_create_bufs() only. But if you have better suggestions, then let me know! Regards, Hans > if (q->io_modes & VB2_MMAP) > *caps |= V4L2_BUF_CAP_SUPPORTS_MMAP; > if (q->io_modes & VB2_USERPTR) > @@ -762,6 +763,7 @@ 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 = vb2_get_num_buffers(q); > + create->max_num_buffers = q->max_num_buffers; > if (create->count == 0) > return ret != -EBUSY ? ret : 0; > > diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c > index 9b1de54ce379..628b013ca0c4 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_num_buffers); > v4l_print_format(&p->format, write_only); > } > > diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h > index c3d4e490ce7c..13ddb5abf584 100644 > --- a/include/uapi/linux/videodev2.h > +++ b/include/uapi/linux/videodev2.h > @@ -1035,6 +1035,7 @@ 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_MAX_NUM_BUFFERS (1 << 7) > > /** > * struct v4l2_plane - plane info for multi-planar buffers > @@ -2605,6 +2606,9 @@ 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_num_buffers: if V4L2_BUF_CAP_SUPPORTS_MAX_NUM_BUFFERS capability flag is set if -> if the > + * this field indicate the maximum possible number of buffers indicate -> indicates > + * for this queue. > * @reserved: future extensions > */ > struct v4l2_create_buffers { > @@ -2614,7 +2618,8 @@ struct v4l2_create_buffers { > struct v4l2_format format; > __u32 capabilities; > __u32 flags; > - __u32 reserved[6]; > + __u32 max_num_buffers; > + __u32 reserved[5]; > }; > > /* Regards, Hans
diff --git a/Documentation/userspace-api/media/v4l/vidioc-create-bufs.rst b/Documentation/userspace-api/media/v4l/vidioc-create-bufs.rst index a048a9f6b7b6..380195c2a00a 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_num_buffers`` + - If V4L2_BUF_CAP_SUPPORTS_MAX_NUM_BUFFERS 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.rst index 099fa6695167..0b3a41a45d05 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-MAX-NUM-BUFFERS: .. raw:: latex diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c index f3cf4b235c1f..201438ffd13f 100644 --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c @@ -680,6 +680,7 @@ 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_MAX_NUM_BUFFERS; if (q->io_modes & VB2_MMAP) *caps |= V4L2_BUF_CAP_SUPPORTS_MMAP; if (q->io_modes & VB2_USERPTR) @@ -762,6 +763,7 @@ 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 = vb2_get_num_buffers(q); + create->max_num_buffers = q->max_num_buffers; if (create->count == 0) return ret != -EBUSY ? ret : 0; diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c index 9b1de54ce379..628b013ca0c4 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_num_buffers); v4l_print_format(&p->format, write_only); } diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h index c3d4e490ce7c..13ddb5abf584 100644 --- a/include/uapi/linux/videodev2.h +++ b/include/uapi/linux/videodev2.h @@ -1035,6 +1035,7 @@ 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_MAX_NUM_BUFFERS (1 << 7) /** * struct v4l2_plane - plane info for multi-planar buffers @@ -2605,6 +2606,9 @@ 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_num_buffers: if V4L2_BUF_CAP_SUPPORTS_MAX_NUM_BUFFERS capability flag is set + * this field indicate the maximum possible number of buffers + * for this queue. * @reserved: future extensions */ struct v4l2_create_buffers { @@ -2614,7 +2618,8 @@ struct v4l2_create_buffers { struct v4l2_format format; __u32 capabilities; __u32 flags; - __u32 reserved[6]; + __u32 max_num_buffers; + __u32 reserved[5]; }; /*
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@collabora.com> --- .../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 | 2 ++ drivers/media/v4l2-core/v4l2-ioctl.c | 4 ++-- include/uapi/linux/videodev2.h | 7 ++++++- 5 files changed, 17 insertions(+), 5 deletions(-)