Re: [RFCv4 10/21] videodev2.h: Add request_fd field to v4l2_buffer
From: Alexandre Courbot
Date: Wed Feb 21 2018 - 01:03:04 EST
On Wed, Feb 21, 2018 at 12:20 AM, Hans Verkuil <hverkuil@xxxxxxxxx> wrote:
> On 02/20/18 05:44, Alexandre Courbot wrote:
>> From: Hans Verkuil <hans.verkuil@xxxxxxxxx>
>>
>> When queuing buffers allow for passing the request that should
>> be associated with this buffer.
>>
>> Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
>> [acourbot@xxxxxxxxxxxx: make request ID 32-bit]
>> Signed-off-by: Alexandre Courbot <acourbot@xxxxxxxxxxxx>
>> ---
>> drivers/media/common/videobuf2/videobuf2-v4l2.c | 2 +-
>> drivers/media/usb/cpia2/cpia2_v4l.c | 2 +-
>> drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 9 ++++++---
>> drivers/media/v4l2-core/v4l2-ioctl.c | 4 ++--
>> include/uapi/linux/videodev2.h | 3 ++-
>> 5 files changed, 12 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
>> index 886a2d8d5c6c..6d4d184aa68e 100644
>> --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
>> +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
>> @@ -203,7 +203,7 @@ static void __fill_v4l2_buffer(struct vb2_buffer *vb, void *pb)
>> b->timestamp = ns_to_timeval(vb->timestamp);
>> b->timecode = vbuf->timecode;
>> b->sequence = vbuf->sequence;
>> - b->reserved2 = 0;
>> + b->request_fd = 0;
>> b->reserved = 0;
>>
>> if (q->is_multiplanar) {
>> diff --git a/drivers/media/usb/cpia2/cpia2_v4l.c b/drivers/media/usb/cpia2/cpia2_v4l.c
>> index 99f106b13280..af42ce3ceb48 100644
>> --- a/drivers/media/usb/cpia2/cpia2_v4l.c
>> +++ b/drivers/media/usb/cpia2/cpia2_v4l.c
>> @@ -948,7 +948,7 @@ static int cpia2_dqbuf(struct file *file, void *fh, struct v4l2_buffer *buf)
>> buf->sequence = cam->buffers[buf->index].seq;
>> buf->m.offset = cam->buffers[buf->index].data - cam->frame_buffer;
>> buf->length = cam->frame_size;
>> - buf->reserved2 = 0;
>> + buf->request_fd = 0;
>> buf->reserved = 0;
>> memset(&buf->timecode, 0, sizeof(buf->timecode));
>>
>> diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
>> index 5198c9eeb348..32bf47489a2e 100644
>> --- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
>> +++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
>> @@ -386,7 +386,7 @@ struct v4l2_buffer32 {
>> __s32 fd;
>> } m;
>> __u32 length;
>> - __u32 reserved2;
>> + __s32 request_fd;
>> __u32 reserved;
>> };
>>
>> @@ -486,6 +486,7 @@ static int get_v4l2_buffer32(struct v4l2_buffer __user *kp,
>> {
>> u32 type;
>> u32 length;
>> + s32 request_fd;
>> enum v4l2_memory memory;
>> struct v4l2_plane32 __user *uplane32;
>> struct v4l2_plane __user *uplane;
>> @@ -500,7 +501,9 @@ static int get_v4l2_buffer32(struct v4l2_buffer __user *kp,
>> get_user(memory, &up->memory) ||
>> put_user(memory, &kp->memory) ||
>> get_user(length, &up->length) ||
>> - put_user(length, &kp->length))
>> + put_user(length, &kp->length) ||
>> + get_user(request_fd, &up->request_fd) ||
>> + put_user(request_fd, &kp->request_fd))
>> return -EFAULT;
>>
>> if (V4L2_TYPE_IS_OUTPUT(type))
>> @@ -604,7 +607,7 @@ static int put_v4l2_buffer32(struct v4l2_buffer __user *kp,
>> assign_in_user(&up->timestamp.tv_usec, &kp->timestamp.tv_usec) ||
>> copy_in_user(&up->timecode, &kp->timecode, sizeof(kp->timecode)) ||
>> assign_in_user(&up->sequence, &kp->sequence) ||
>> - assign_in_user(&up->reserved2, &kp->reserved2) ||
>> + assign_in_user(&up->request_fd, &kp->request_fd) ||
>> assign_in_user(&up->reserved, &kp->reserved) ||
>> get_user(length, &kp->length) ||
>> put_user(length, &up->length))
>> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
>> index 260288ca4f55..7bfeaf233d5a 100644
>> --- a/drivers/media/v4l2-core/v4l2-ioctl.c
>> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
>> @@ -437,13 +437,13 @@ static void v4l_print_buffer(const void *arg, bool write_only)
>> const struct v4l2_plane *plane;
>> int i;
>>
>> - pr_cont("%02ld:%02d:%02d.%08ld index=%d, type=%s, flags=0x%08x, field=%s, sequence=%d, memory=%s",
>> + pr_cont("%02ld:%02d:%02d.%08ld index=%d, type=%s, request_fd=%u, flags=0x%08x, field=%s, sequence=%d, memory=%s",
>> p->timestamp.tv_sec / 3600,
>> (int)(p->timestamp.tv_sec / 60) % 60,
>> (int)(p->timestamp.tv_sec % 60),
>> (long)p->timestamp.tv_usec,
>> p->index,
>> - prt_names(p->type, v4l2_type_names),
>> + prt_names(p->type, v4l2_type_names), p->request_fd,
>> p->flags, prt_names(p->field, v4l2_field_names),
>> p->sequence, prt_names(p->memory, v4l2_memory_names));
>>
>> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
>> index 982718965180..4fd46ae8fad5 100644
>> --- a/include/uapi/linux/videodev2.h
>> +++ b/include/uapi/linux/videodev2.h
>> @@ -909,6 +909,7 @@ struct v4l2_plane {
>> * @length: size in bytes of the buffer (NOT its payload) for single-plane
>> * buffers (when type != *_MPLANE); number of elements in the
>> * planes array for multi-plane buffers
>> + * @request_fd: fd of the request that this buffer should use
>> *
>> * Contains data exchanged by application and driver using one of the Streaming
>> * I/O methods.
>> @@ -932,7 +933,7 @@ struct v4l2_buffer {
>> __s32 fd;
>> } m;
>> __u32 length;
>> - __u32 reserved2;
>> + __s32 request_fd;
>
> This should be:
>
> union {
> __s32 request_fd;
> __u32 reserved2;
> };
>
> Otherwise any existing application that sets 'reserved2 = 0;' would fail.
> I encountered this issue when compiling v4l-utils.
Fixed, thanks!