[libcamera-devel] [PATCH] v4l2: V4L2CameraProxy: Add EXPBUF as one of the supported ioctl
Vedant Paranjape
vedantparanjape160201 at gmail.com
Sat Nov 27 21:22:55 CET 2021
Hello Laurent,
Thanks for the review.
On Sun, 28 Nov, 2021, 01:30 Laurent Pinchart,
<laurent.pinchart at ideasonboard.com> wrote:
>
> Hi Vedant,
>
> Thank you for the patch.
>
> On Sun, Nov 28, 2021 at 12:54:40AM +0530, Vedant Paranjape wrote:
> > To support DMABUF as one of the memory buffer, we need to implement
> > EXPBUF in the v4l2 compat layer.
> >
> > This patch implements vidioc_expbuf as one of the supported ioctls.
> >
> > Reference issue: https://bugs.libcamera.org/show_bug.cgi?id=89
>
> We use
>
> Bug: https://bugs.libcamera.org/show_bug.cgi?id=89
Noted.
>
> > Signed-off-by: Vedant Paranjape <vedantparanjape160201 at gmail.com>
> > ---
> > src/v4l2/v4l2_camera_proxy.cpp | 41 +++++++++++++++++++++++++++++++++-
> > src/v4l2/v4l2_camera_proxy.h | 1 +
> > 2 files changed, 41 insertions(+), 1 deletion(-)
> >
> > diff --git a/src/v4l2/v4l2_camera_proxy.cpp b/src/v4l2/v4l2_camera_proxy.cpp
> > index 3610e63cade3..03e3564bfed5 100644
> > --- a/src/v4l2/v4l2_camera_proxy.cpp
> > +++ b/src/v4l2/v4l2_camera_proxy.cpp
> > @@ -160,7 +160,8 @@ bool V4L2CameraProxy::validateBufferType(uint32_t type)
> >
> > bool V4L2CameraProxy::validateMemoryType(uint32_t memory)
> > {
> > - return memory == V4L2_MEMORY_MMAP;
> > + return (memory == V4L2_MEMORY_MMAP) ||
> > + (memory == V4L2_MEMORY_DMABUF);
>
> This has the side effect that, for instance, REQBUFS will accept the
> memory type DMABUF, but without DMABUF support actually implemented. Why
> do you need this change as part of this patch ?
Right, will remove it.
> > }
> >
> > void V4L2CameraProxy::setFmtFromConfig(const StreamConfiguration &streamConfig)
> > @@ -624,6 +625,40 @@ int V4L2CameraProxy::vidioc_dqbuf(V4L2CameraFile *file, struct v4l2_buffer *arg,
> > return 0;
> > }
> >
> > +int V4L2CameraProxy::vidioc_expbuf(V4L2CameraFile *file, struct v4l2_exportbuffer *arg)
> > +{
> > + LOG(V4L2Compat, Debug) << "Servicing vidioc_expbuf fd = " << file->efd();
> > + /* \todo Verify that the memory type is MMAP when adding DMABUF support */
> > + if (!validateBufferType(arg->type))
> > + return -EINVAL;
> > +
> > + if (arg->index >= bufferCount_)
> > + return -EINVAL;
> > +
> > + if (arg->flags & ~(O_CLOEXEC | O_ACCMODE))
> > + return -EINVAL;
> > +
> > + LOG(V4L2Compat, Debug) << arg->index << " : index of the buffer";
> > +
> > + if (file->priority() < maxPriority())
> > + return -EBUSY;
> > +
> > + if (!hasOwnership(file) && owner_)
> > + return -EBUSY;
>
> I don't think this is right, you can't EXPBUF without calling REQBUFS
> first, which has an impact on ownership.
But, there's no way to know that reqbuf is the owner and was called before this.
> No cargo cult copy&paste please.
LMAO, okay ;)
> > +
> > + memset(arg->reserved, 0, sizeof(arg->reserved));
> > +
> > + arg->fd = fcntl(buffers_[arg->index].m.fd,
> > + arg->flags & O_CLOEXEC ? F_DUPFD_CLOEXEC : F_DUPFD, 0);
> > + arg->fd = fcntl(arg->fd, F_SETFL, 0);
>
> 0 ?
>
> > +
> > + LOG(V4L2Compat, Debug) << "Exported buffer at index: " << arg->index;
> > +
> > + acquire(file);
>
> Same comment regarding ownership.
>
> > +
> > + return 0;
> > +}
> > +
> > int V4L2CameraProxy::vidioc_streamon(V4L2CameraFile *file, int *arg)
> > {
> > LOG(V4L2Compat, Debug) << "Servicing vidioc_streamon fd = " << file->efd();
> > @@ -685,6 +720,7 @@ const std::set<unsigned long> V4L2CameraProxy::supportedIoctls_ = {
> > VIDIOC_QUERYBUF,
> > VIDIOC_QBUF,
> > VIDIOC_DQBUF,
> > + VIDIOC_EXPBUF,
> > VIDIOC_STREAMON,
> > VIDIOC_STREAMOFF,
> > };
> > @@ -755,6 +791,9 @@ int V4L2CameraProxy::ioctl(V4L2CameraFile *file, unsigned long request, void *ar
> > case VIDIOC_DQBUF:
> > ret = vidioc_dqbuf(file, static_cast<struct v4l2_buffer *>(arg), &locker);
> > break;
> > + case VIDIOC_EXPBUF:
> > + ret = vidioc_expbuf(file, static_cast<struct v4l2_exportbuffer *>(arg));
> > + break;
> > case VIDIOC_STREAMON:
> > ret = vidioc_streamon(file, static_cast<int *>(arg));
> > break;
> > diff --git a/src/v4l2/v4l2_camera_proxy.h b/src/v4l2/v4l2_camera_proxy.h
> > index fccec241879d..81ef7788e9fe 100644
> > --- a/src/v4l2/v4l2_camera_proxy.h
> > +++ b/src/v4l2/v4l2_camera_proxy.h
> > @@ -58,6 +58,7 @@ private:
> > int vidioc_qbuf(V4L2CameraFile *file, struct v4l2_buffer *arg);
> > int vidioc_dqbuf(V4L2CameraFile *file, struct v4l2_buffer *arg,
> > libcamera::MutexLocker *locker);
> > + int vidioc_expbuf(V4L2CameraFile *file, struct v4l2_exportbuffer *arg);
> > int vidioc_streamon(V4L2CameraFile *file, int *arg);
> > int vidioc_streamoff(V4L2CameraFile *file, int *arg);
> >
>
> --
> Regards,
>
> Laurent Pinchart
Regards,
Vedant Paranjape
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