Messages in this thread | | | Date | Mon, 3 Jul 2023 12:35:52 +0200 | Subject | Re: [PATCH v3 10/11] media: v4l2: Add DELETE_BUF ioctl | From | Benjamin Gaignard <> |
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Le 03/07/2023 à 11:20, Hsia-Jun Li a écrit : > > On 7/3/23 16:52, Benjamin Gaignard wrote: >> CAUTION: Email originated externally, do not click links or open >> attachments unless you recognize the sender and know the content is >> safe. >> >> >> Le 03/07/2023 à 10:19, Hsia-Jun Li a écrit : >>> >>> On 7/3/23 16:12, Benjamin Gaignard wrote: >>>> CAUTION: Email originated externally, do not click links or open >>>> attachments unless you recognize the sender and know the content is >>>> safe. >>>> >>>> >>>> Le 30/06/2023 à 11:43, Hsia-Jun Li a écrit : >>>>> >>>>> On 6/27/23 16:47, Hsia-Jun Li wrote: >>>>>> CAUTION: Email originated externally, do not click links or open >>>>>> attachments unless you recognize the sender and know the content is >>>>>> safe. >>>>>> >>>>>> >>>>>> On 6/27/23 16:43, Benjamin Gaignard wrote: >>>>>>> CAUTION: Email originated externally, do not click links or open >>>>>>> attachments unless you recognize the sender and know the content is >>>>>>> safe. >>>>>>> >>>>>>> >>>>>>> Le 27/06/2023 à 09:30, Hsia-Jun Li a écrit : >>>>>>>> >>>>>>>> On 6/22/23 21:13, Benjamin Gaignard wrote: >>>>>>>>> CAUTION: Email originated externally, do not click links or open >>>>>>>>> attachments unless you recognize the sender and know the >>>>>>>>> content is >>>>>>>>> safe. >>>>>>>>> >>>>>>>>> >>>>>>>>> VIDIOC_DELETE_BUF ioctl allows to delete a buffer from a queue. >>>>>>>>> >>>>>>>>> Signed-off-by: Benjamin Gaignard >>>>>>>>> <benjamin.gaignard@collabora.com> >>>>>>>>> --- >>>>>>>>> .../userspace-api/media/v4l/user-func.rst | 1 + >>>>>>>>> .../media/v4l/vidioc-delete-buf.rst | 51 >>>>>>>>> +++++++++++++++++++ >>>>>>>>> .../media/common/videobuf2/videobuf2-core.c | 33 ++++++++++++ >>>>>>>>> .../media/common/videobuf2/videobuf2-v4l2.c | 6 +++ >>>>>>>>> drivers/media/v4l2-core/v4l2-dev.c | 1 + >>>>>>>>> drivers/media/v4l2-core/v4l2-ioctl.c | 10 ++++ >>>>>>>>> include/media/v4l2-ioctl.h | 4 ++ >>>>>>>>> include/media/videobuf2-core.h | 9 ++++ >>>>>>>>> include/media/videobuf2-v4l2.h | 11 ++++ >>>>>>>>> include/uapi/linux/videodev2.h | 2 + >>>>>>>>> 10 files changed, 128 insertions(+) >>>>>>>>> create mode 100644 >>>>>>>>> Documentation/userspace-api/media/v4l/vidioc-delete-buf.rst >>>>>>>>> >>>>>>>>> diff --git a/Documentation/userspace-api/media/v4l/user-func.rst >>>>>>>>> b/Documentation/userspace-api/media/v4l/user-func.rst >>>>>>>>> index 15ff0bf7bbe6..8c74016e12fd 100644 >>>>>>>>> --- a/Documentation/userspace-api/media/v4l/user-func.rst >>>>>>>>> +++ b/Documentation/userspace-api/media/v4l/user-func.rst >>>>>>>>> @@ -17,6 +17,7 @@ Function Reference >>>>>>>>> vidioc-dbg-g-chip-info >>>>>>>>> vidioc-dbg-g-register >>>>>>>>> vidioc-decoder-cmd >>>>>>>>> + vidioc-delete-buf >>>>>>>>> vidioc-dqevent >>>>>>>>> vidioc-dv-timings-cap >>>>>>>>> vidioc-encoder-cmd >>>>>>>>> diff --git >>>>>>>>> a/Documentation/userspace-api/media/v4l/vidioc-delete-buf.rst >>>>>>>>> b/Documentation/userspace-api/media/v4l/vidioc-delete-buf.rst >>>>>>>>> new file mode 100644 >>>>>>>>> index 000000000000..0e7ce58f91bc >>>>>>>>> --- /dev/null >>>>>>>>> +++ b/Documentation/userspace-api/media/v4l/vidioc-delete-buf.rst >>>>>>>>> @@ -0,0 +1,51 @@ >>>>>>>>> +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later >>>>>>>>> +.. c:namespace:: V4L >>>>>>>>> + >>>>>>>>> +.. _VIDIOC_DELETE_BUF: >>>>>>>>> + >>>>>>>>> +************************ >>>>>>>>> +ioctl VIDIOC_DELETE_BUF >>>>>>>>> +************************ >>>>>>>>> + >>>>>>>>> +Name >>>>>>>>> +==== >>>>>>>>> + >>>>>>>>> +VIDIOC_DELETE_BUF - Delete a buffer from a queue >>>>>>>>> + >>>>>>>>> +Synopsis >>>>>>>>> +======== >>>>>>>>> + >>>>>>>>> +.. c:macro:: VIDIOC_DELETE_BUF >>>>>>>>> + >>>>>>>>> +``int ioctl(int fd, VIDIOC_DELETE_BUF, struct v4l2_buffer >>>>>>>>> *argp)`` >>>>>>>>> + >>>>>>>>> +Arguments >>>>>>>>> +========= >>>>>>>>> + >>>>>>>>> +``fd`` >>>>>>>>> + File descriptor returned by :c:func:`open()`. >>>>>>>>> + >>>>>>>>> +``argp`` >>>>>>>>> + Pointer to struct :c:type:`v4l2_buffer`. >>>>>>>>> + >>>>>>>>> +Description >>>>>>>>> +=========== >>>>>>>>> + >>>>>>>>> +Applications can optionally call the :ref:`VIDIOC_DELETE_BUF` >>>>>>>>> ioctl to >>>>>>>>> +delete a buffer from a queue. >>>>>>>>> + >>>>>>>>> +The struct :c:type:`v4l2_buffer` structure is specified in >>>>>>>>> +:ref:`buffer`. >>>>>>>>> + >>>>>>>>> +Return Value >>>>>>>>> +============ >>>>>>>>> + >>>>>>>>> +On success 0 is returned, on error -1 and the ``errno`` >>>>>>>>> variable is >>>>>>>>> set >>>>>>>>> +appropriately. The generic error codes are described at the >>>>>>>>> +:ref:`Generic Error Codes <gen-errors>` chapter. >>>>>>>>> + >>>>>>>>> +EBUSY >>>>>>>>> + File I/O is in progress. >>>>>>>>> + >>>>>>>>> +EINVAL >>>>>>>>> + The buffer ``index`` doesn't exist in the queue. >>>>>>>>> diff --git a/drivers/media/common/videobuf2/videobuf2-core.c >>>>>>>>> b/drivers/media/common/videobuf2/videobuf2-core.c >>>>>>>>> index 899783f67580..aa546c972c3d 100644 >>>>>>>>> --- a/drivers/media/common/videobuf2/videobuf2-core.c >>>>>>>>> +++ b/drivers/media/common/videobuf2/videobuf2-core.c >>>>>>>>> @@ -1637,6 +1637,39 @@ int vb2_core_prepare_buf(struct vb2_queue >>>>>>>>> *q, >>>>>>>>> unsigned int index, void *pb) >>>>>>>>> } >>>>>>>>> EXPORT_SYMBOL_GPL(vb2_core_prepare_buf); >>>>>>>>> >>>>>>>>> +int vb2_core_delete_buf(struct vb2_queue *q, unsigned int index) >>>>>>>>> +{ >>>>>>>>> + struct vb2_buffer *vb; >>>>>>>>> + >>>>>>>>> + vb = vb2_get_buffer(q, index); >>>>>>>>> + if (!vb) { >>>>>>>>> + dprintk(q, 1, "invalid buffer index %d\n", >>>>>>>>> index); >>>>>>>>> + return -EINVAL; >>>>>>>>> + } >>>>>>>>> + >>>>>>>>> + if (vb->state != VB2_BUF_STATE_DEQUEUED) { >>>>>>>>> + dprintk(q, 1, "can't delete non dequeued buffer >>>>>>>>> index >>>>>>>>> %d\n", index); >>>>>>>>> + return -EINVAL; >>>>>>>>> + } >>>>>>>>> + >>>>>>>> I know the driver could implement its own >>>>>>>> v4l2_ioctl_ops->vidioc_delete_buf() that check whether a buffer is >>>>>>>> used by the hardware as a future reference frame. >>>>>>>> But I think we need a flag to let the user know which buffer is >>>>>>>> still >>>>>>>> used by the hardware. >>>>>>>> Alternative ref case is safe, we only know it's existing when >>>>>>>> it is >>>>>>>> dequeued in current V4L2 buffer mechanism. >>>>>>>> While the Golden reference frame, such long term reference frame >>>>>>>> could >>>>>>>> last much longer. >>>>>>> >>>>>>> It is up to userland stack to know frames life time, it got the >>>>>>> information for that. >>>>>> >>>>>> That is true for the stateless codec driver. >>>>>> >>>>>> While application for stateful decoder could never do that. It also >>>>>> breaks what the document said: >>>>>> >>>>>> "The backing memory of |CAPTURE| buffers that are used as reference >>>>>> frames by the stream may be read by the hardware even after they are >>>>>> dequeued. Consequently, the client should avoid writing into this >>>>>> memory >>>>>> while the |CAPTURE| queue is streaming. Failure to observe this may >>>>>> result in corruption of decoded frames." >>>>>> >>>>>>> >>>>>>>>> + if (vb->planes[0].mem_priv) >>>>>>>>> + call_void_vb_qop(vb, buf_cleanup, vb); >>>>>>>>> + >>>>>>>>> + /* Free MMAP buffers or release USERPTR buffers */ >>>>>>>>> + if (q->memory == VB2_MEMORY_MMAP) >>>>>>>>> + __vb2_buf_mem_free(vb); >>>>> >>>>> Here is another problem for the existing application, the mmap() from >>>>> the mmap offset or exportbuffer fd would not create a reference to >>>>> buffer in this step(while the exportbuffer would create one itself). >>>>> >>>>> When you delete a buffer, you may not release it from its virtual >>>>> memory space, leaving a corrupted virtual memory space. Also this >>>>> behavior is right, because mmap(2) says: >>>>> >>>>> "After the mmap() call has returned, the file descriptor, fd, can >>>>> be closed immediately without invalidating the map‐ping." >>>> >>>> Existing applications do not call DELETE_BUF ioctl and when call it >>>> they will be aware that the buffer is removed. >>>> I have done it in GStreamer: >>>> https://urldefense.proofpoint.com/v2/url?u=https-3A__gitlab.freedesktop.org_benjamin.gaignard1_gstreamer_-2D_commit_fca0fbc934f4440693ce0ff6c8dc8a2e5f5f17d9&d=DwIDaQ&c=7dfBJ8cXbWjhc0BhImu8wVIoUFmBzj1s88r8EGyM0UY&r=P4xb2_7biqBxD4LGGPrSV6j-jf3C3xlR7PXU-mLTeZE&m=TGH9toTzGRfO5aBsfaMvGbcOw-28q6cPmpX6vScbHjpCtaLtb-RuvBvsJ0z9RvAB&s=Ufl1ccfRZf2EhnfCBvnQzRJV9CDhGxl5spe9WNECspU&e= >>>> >>>> >>> >>> I have read that. >>> >>> There is not a VP8 parser in Gstreamer, while a parser would not work >>> when deal with the secure video(userspace can't access the data >>> context at all). >>> >>> Besides, this adds extra work for the application for a stateful codec >>> driver. The application need to parser the bitstream and track the dpb. >>> >>> I don't mind if you could fix the nonfiction mechanism for those >>> non-display frame and internal reference state. >>> >>> That could be requirement for codec firmware that its driver could >>> support this DELETE_BUF ioctl() feature. >> >> Sorry I don't see the link with my patches here... >> I have work on non-secure VP9 on stateless codec. >> DELETE_BUF ioctl is optional and the main goal is to offer a way to >> applications >> to save memory if they know when they could delete buffers without risk. > > I try to explain why I think this design in not "complete". One > problem resolved, more problems would occur. > > > For non-secure video, those applications have worked: > > - It would break what stateful means here, application need to > acquire(parse) the information that driver should offer. > > Or it would break the decoding model. > > - Your Gstreamer sample code or this design won't work for AV1. why ? > > For all the future possible secure video: > > - This feature could never be used from the current design. > > >> >>> >>>> >>>> Regards, >>>> Benjamin >>>> >>>>> >>>>>>>>> + else if (q->memory == VB2_MEMORY_DMABUF) >>>>>>>>> + __vb2_buf_dmabuf_put(vb); >>>>>>>>> + else >>>>>>>>> + __vb2_buf_userptr_put(vb); >>>>>>>>> + >>>>>>>>> + vb2_queue_remove_buffer(q, vb); >>>>>>>>> + kfree(vb); >>>>>>>>> + >>>>>>>>> + dprintk(q, 2, "buffer %d deleted\n", index); >>>>>>>>> + return 0; >>>>>>>>> +} >>>>>>>>> + >>>>>>>>> /* >>>>>>>>> * vb2_start_streaming() - Attempt to start streaming. >>>>>>>>> * @q: videobuf2 queue >>>>>>>>> diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c >>>>>>>>> b/drivers/media/common/videobuf2/videobuf2-v4l2.c >>>>>>>>> index 724135d41f7f..cea666c17b41 100644 >>>>>>>>> --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c >>>>>>>>> +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c >>>>>>>>> @@ -751,6 +751,12 @@ int vb2_prepare_buf(struct vb2_queue *q, >>>>>>>>> struct >>>>>>>>> media_device *mdev, >>>>>>>>> } >>>>>>>>> EXPORT_SYMBOL_GPL(vb2_prepare_buf); >>>>>>>>> >>>>>>>>> +int vb2_delete_buf(struct vb2_queue *q, struct v4l2_buffer *b) >>>>>>>>> +{ >>>>>>>>> + return vb2_core_delete_buf(q, b->index); >>>>>>>>> +} >>>>>>>>> +EXPORT_SYMBOL_GPL(vb2_delete_buf); >>>>>>>>> + >>>>>>>>> int vb2_create_bufs(struct vb2_queue *q, struct >>>>>>>>> v4l2_create_buffers >>>>>>>>> *create) >>>>>>>>> { >>>>>>>>> unsigned requested_planes = 1; >>>>>>>>> diff --git a/drivers/media/v4l2-core/v4l2-dev.c >>>>>>>>> b/drivers/media/v4l2-core/v4l2-dev.c >>>>>>>>> index f81279492682..80ace2e1e932 100644 >>>>>>>>> --- a/drivers/media/v4l2-core/v4l2-dev.c >>>>>>>>> +++ b/drivers/media/v4l2-core/v4l2-dev.c >>>>>>>>> @@ -720,6 +720,7 @@ static void determine_valid_ioctls(struct >>>>>>>>> video_device *vdev) >>>>>>>>> SET_VALID_IOCTL(ops, VIDIOC_PREPARE_BUF, >>>>>>>>> vidioc_prepare_buf); >>>>>>>>> SET_VALID_IOCTL(ops, VIDIOC_STREAMON, >>>>>>>>> vidioc_streamon); >>>>>>>>> SET_VALID_IOCTL(ops, VIDIOC_STREAMOFF, >>>>>>>>> vidioc_streamoff); >>>>>>>>> + SET_VALID_IOCTL(ops, VIDIOC_DELETE_BUF, >>>>>>>>> vidioc_delete_buf); >>>>>>>>> } >>>>>>>>> >>>>>>>>> if (is_vid || is_vbi || is_meta) { >>>>>>>>> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c >>>>>>>>> b/drivers/media/v4l2-core/v4l2-ioctl.c >>>>>>>>> index a858acea6547..1c737279d3ef 100644 >>>>>>>>> --- a/drivers/media/v4l2-core/v4l2-ioctl.c >>>>>>>>> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c >>>>>>>>> @@ -2156,6 +2156,15 @@ static int v4l_prepare_buf(const struct >>>>>>>>> v4l2_ioctl_ops *ops, >>>>>>>>> return ret ? ret : ops->vidioc_prepare_buf(file, fh, b); >>>>>>>>> } >>>>>>>>> >>>>>>>>> +static int v4l_delete_buf(const struct v4l2_ioctl_ops *ops, >>>>>>>>> + struct file *file, void *fh, void *arg) >>>>>>>>> +{ >>>>>>>>> + struct v4l2_buffer *b = arg; >>>>>>>>> + int ret = check_fmt(file, b->type); >>>>>>>>> + >>>>>>>>> + return ret ? ret : ops->vidioc_delete_buf(file, fh, b); >>>>>>>>> +} >>>>>>>>> + >>>>>>>>> static int v4l_g_parm(const struct v4l2_ioctl_ops *ops, >>>>>>>>> struct file *file, void *fh, >>>>>>>>> void >>>>>>>>> *arg) >>>>>>>>> { >>>>>>>>> @@ -2905,6 +2914,7 @@ static const struct v4l2_ioctl_info >>>>>>>>> v4l2_ioctls[] = { >>>>>>>>> IOCTL_INFO(VIDIOC_ENUM_FREQ_BANDS, v4l_enum_freq_bands, >>>>>>>>> v4l_print_freq_band, 0), >>>>>>>>> IOCTL_INFO(VIDIOC_DBG_G_CHIP_INFO, v4l_dbg_g_chip_info, >>>>>>>>> v4l_print_dbg_chip_info, INFO_FL_CLEAR(v4l2_dbg_chip_info, >>>>>>>>> match)), >>>>>>>>> IOCTL_INFO(VIDIOC_QUERY_EXT_CTRL, v4l_query_ext_ctrl, >>>>>>>>> v4l_print_query_ext_ctrl, INFO_FL_CTRL | >>>>>>>>> INFO_FL_CLEAR(v4l2_query_ext_ctrl, id)), >>>>>>>>> + IOCTL_INFO(VIDIOC_DELETE_BUF, v4l_delete_buf, >>>>>>>>> v4l_print_buffer, INFO_FL_QUEUE), >>>>>>>>> }; >>>>>>>>> #define V4L2_IOCTLS ARRAY_SIZE(v4l2_ioctls) >>>>>>>>> >>>>>>>>> diff --git a/include/media/v4l2-ioctl.h >>>>>>>>> b/include/media/v4l2-ioctl.h >>>>>>>>> index edb733f21604..2f232ed884c7 100644 >>>>>>>>> --- a/include/media/v4l2-ioctl.h >>>>>>>>> +++ b/include/media/v4l2-ioctl.h >>>>>>>>> @@ -163,6 +163,8 @@ struct v4l2_fh; >>>>>>>>> * :ref:`VIDIOC_CREATE_BUFS <vidioc_create_bufs>` ioctl >>>>>>>>> * @vidioc_prepare_buf: pointer to the function that implements >>>>>>>>> * :ref:`VIDIOC_PREPARE_BUF <vidioc_prepare_buf>` ioctl >>>>>>>>> + * @vidioc_delete_buf: pointer to the function that implements >>>>>>>>> + * :ref:`VIDIOC_DELETE_BUF <vidioc_delete_buf>` ioctl >>>>>>>>> * @vidioc_overlay: pointer to the function that implements >>>>>>>>> * :ref:`VIDIOC_OVERLAY <vidioc_overlay>` ioctl >>>>>>>>> * @vidioc_g_fbuf: pointer to the function that implements >>>>>>>>> @@ -422,6 +424,8 @@ struct v4l2_ioctl_ops { >>>>>>>>> struct v4l2_create_buffers >>>>>>>>> *b); >>>>>>>>> int (*vidioc_prepare_buf)(struct file *file, void *fh, >>>>>>>>> struct v4l2_buffer *b); >>>>>>>>> + int (*vidioc_delete_buf)(struct file *file, void *fh, >>>>>>>>> + struct v4l2_buffer *b); >>>>>>>>> >>>>>>>>> int (*vidioc_overlay)(struct file *file, void *fh, >>>>>>>>> unsigned >>>>>>>>> int i); >>>>>>>>> int (*vidioc_g_fbuf)(struct file *file, void *fh, >>>>>>>>> diff --git a/include/media/videobuf2-core.h >>>>>>>>> b/include/media/videobuf2-core.h >>>>>>>>> index 080b783d608d..0f9e68f76b77 100644 >>>>>>>>> --- a/include/media/videobuf2-core.h >>>>>>>>> +++ b/include/media/videobuf2-core.h >>>>>>>>> @@ -840,6 +840,15 @@ int vb2_core_create_bufs(struct vb2_queue >>>>>>>>> *q, >>>>>>>>> enum vb2_memory memory, >>>>>>>>> */ >>>>>>>>> int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int >>>>>>>>> index, >>>>>>>>> void *pb); >>>>>>>>> >>>>>>>>> +/** >>>>>>>>> + * vb2_core_delete_buf() - >>>>>>>>> + * @q: pointer to &struct vb2_queue with videobuf2 queue. >>>>>>>>> + * @index: id number of the buffer. >>>>>>>>> + * >>>>>>>>> + * Return: returns zero on success; an error code otherwise. >>>>>>>>> + */ >>>>>>>>> +int vb2_core_delete_buf(struct vb2_queue *q, unsigned int >>>>>>>>> index); >>>>>>>>> + >>>>>>>>> /** >>>>>>>>> * vb2_core_qbuf() - Queue a buffer from userspace >>>>>>>>> * >>>>>>>>> diff --git a/include/media/videobuf2-v4l2.h >>>>>>>>> b/include/media/videobuf2-v4l2.h >>>>>>>>> index 88a7a565170e..3beeb4c735f0 100644 >>>>>>>>> --- a/include/media/videobuf2-v4l2.h >>>>>>>>> +++ b/include/media/videobuf2-v4l2.h >>>>>>>>> @@ -114,6 +114,17 @@ int vb2_create_bufs(struct vb2_queue *q, >>>>>>>>> struct >>>>>>>>> v4l2_create_buffers *create); >>>>>>>>> */ >>>>>>>>> int vb2_prepare_buf(struct vb2_queue *q, struct media_device >>>>>>>>> *mdev, >>>>>>>>> struct v4l2_buffer *b); >>>>>>>>> +/** >>>>>>>>> + * vb2_delete_buf() - Delete the buffer from the queue >>>>>>>>> + * >>>>>>>>> + * @q: pointer to &struct vb2_queue with videobuf2 >>>>>>>>> queue. >>>>>>>>> + * @b: buffer structure passed from userspace to >>>>>>>>> + * &v4l2_ioctl_ops->vidioc_delete_buf handler in driver >>>>>>>>> + * >>>>>>>>> + * The return values from this function are intended to be >>>>>>>>> directly >>>>>>>>> returned >>>>>>>>> + * from &v4l2_ioctl_ops->vidioc_delete_buf handler in driver. >>>>>>>>> + */ >>>>>>>>> +int vb2_delete_buf(struct vb2_queue *q, struct v4l2_buffer *b); >>>>>>>>> >>>>>>>>> /** >>>>>>>>> * vb2_qbuf() - Queue a buffer from userspace >>>>>>>>> diff --git a/include/uapi/linux/videodev2.h >>>>>>>>> b/include/uapi/linux/videodev2.h >>>>>>>>> index aee75eb9e686..31bba1915642 100644 >>>>>>>>> --- a/include/uapi/linux/videodev2.h >>>>>>>>> +++ b/include/uapi/linux/videodev2.h >>>>>>>>> @@ -2702,6 +2702,8 @@ struct v4l2_create_buffers { >>>>>>>>> #define VIDIOC_DBG_G_CHIP_INFO _IOWR('V', 102, struct >>>>>>>>> v4l2_dbg_chip_info) >>>>>>>>> >>>>>>>>> #define VIDIOC_QUERY_EXT_CTRL _IOWR('V', 103, struct >>>>>>>>> v4l2_query_ext_ctrl) >>>>>>>>> +#define VIDIOC_DELETE_BUF _IOWR('V', 104, struct >>>>>>>>> v4l2_buffer) >>>>>>>>> + >>>>>>>>> >>>>>>>>> /* Reminder: when adding new ioctls please add support for >>>>>>>>> them to >>>>>>>>> drivers/media/v4l2-core/v4l2-compat-ioctl32.c as well! */ >>>>>>>>> -- >>>>>>>>> 2.39.2 >>>>>>>>> >>>>>> -- >>>>>> Hsia-Jun(Randy) Li >>>>>>
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