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 <[email protected]>
---
.../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);
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];
};
/*
--
2.39.2
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 <[email protected]>
> ---
> .../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];
> };
>
> /*
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 <[email protected]>
>>> ---
>>> .../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];
>>> };
>>> /*
>>
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 <[email protected]>
>> ---
>> .../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];
>> };
>>
>> /*
>