| Message ID | 20230927153558.159278-14-benjamin.gaignard@collabora.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Add DELETE_BUF ioctl | expand |
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@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 | 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.rst > index 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.c > index 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. Regards, Hans > return 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.h > index 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]; > }; > > /*
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@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 | 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.rst >> index 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.c >> index 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, > > Hans > >> return 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.h >> index 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]; >> }; >> >> /* >
On 02/10/2023 15:46, Benjamin Gaignard wrote: > > 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@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 | 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.rst >>> index 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.c >>> index 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... Sorry, I meant to reply to the v9 patch, so yes, it is also in v9 :-) Hans > >> >> Regards, >> >> Hans >> >>> return 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.h >>> index 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]; >>> }; >>> /* >>
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.rst index 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.c index 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); return 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.h index 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]; }; /*
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 | 9 +++++++-- drivers/media/v4l2-core/v4l2-ioctl.c | 4 ++-- include/uapi/linux/videodev2.h | 7 ++++++- 5 files changed, 22 insertions(+), 7 deletions(-)