Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753985AbdLUUgx (ORCPT ); Thu, 21 Dec 2017 15:36:53 -0500 Received: from mail-qk0-f194.google.com ([209.85.220.194]:40555 "EHLO mail-qk0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752601AbdLUUgs (ORCPT ); Thu, 21 Dec 2017 15:36:48 -0500 X-Google-Smtp-Source: ACJfBotgYLzP5EL90/jI1DImfJEndCxPbDaNgspH9KG4fAD6OcQbZQZk5NPDrQLewQ/onHFmBkuTZw== Date: Thu, 21 Dec 2017 18:36:41 -0200 From: Gustavo Padovan To: Mauro Carvalho Chehab Cc: linux-media@vger.kernel.org, Hans Verkuil , Shuah Khan , Pawel Osciak , Alexandre Courbot , Sakari Ailus , Brian Starkey , Thierry Escande , linux-kernel@vger.kernel.org, Gustavo Padovan Subject: Re: [PATCH v6 3/6] [media] vb2: add explicit fence user API Message-ID: <20171221203641.GC12003@jade> References: <20171211182741.29712-1-gustavo@padovan.org> <20171211182741.29712-4-gustavo@padovan.org> <20171221165215.46dc86a5@vento.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171221165215.46dc86a5@vento.lan> User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4572 Lines: 110 2017-12-21 Mauro Carvalho Chehab : > Em Mon, 11 Dec 2017 16:27:38 -0200 > Gustavo Padovan escreveu: > > > From: Gustavo Padovan > > > > Turn the reserved2 field into fence_fd that we will use to send > > an in-fence to the kernel and return an out-fence from the kernel to > > userspace. > > > > Two new flags were added, V4L2_BUF_FLAG_IN_FENCE, that should be used > > when sending a fence to the kernel to be waited on, and > > V4L2_BUF_FLAG_OUT_FENCE, to ask the kernel to give back an out-fence. > > > > v4: > > - make it a union with reserved2 and fence_fd (Hans Verkuil) > > > > v3: > > - make the out_fence refer to the current buffer (Hans Verkuil) > > > > v2: add documentation > > > > Signed-off-by: Gustavo Padovan > > --- > > Documentation/media/uapi/v4l/buffer.rst | 15 +++++++++++++++ > > drivers/media/usb/cpia2/cpia2_v4l.c | 2 +- > > drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 4 ++-- > > drivers/media/v4l2-core/videobuf2-v4l2.c | 2 +- > > include/uapi/linux/videodev2.h | 7 ++++++- > > 5 files changed, 25 insertions(+), 5 deletions(-) > > > > diff --git a/Documentation/media/uapi/v4l/buffer.rst b/Documentation/media/uapi/v4l/buffer.rst > > index ae6ee73f151c..eeefbd2547e7 100644 > > --- a/Documentation/media/uapi/v4l/buffer.rst > > +++ b/Documentation/media/uapi/v4l/buffer.rst > > @@ -648,6 +648,21 @@ Buffer Flags > > - Start Of Exposure. The buffer timestamp has been taken when the > > exposure of the frame has begun. This is only valid for the > > ``V4L2_BUF_TYPE_VIDEO_CAPTURE`` buffer type. > > + * .. _`V4L2-BUF-FLAG-IN-FENCE`: > > + > > + - ``V4L2_BUF_FLAG_IN_FENCE`` > > + - 0x00200000 > > + - Ask V4L2 to wait on fence passed in ``fence_fd`` field. The buffer > > + won't be queued to the driver until the fence signals. > > + > > + * .. _`V4L2-BUF-FLAG-OUT-FENCE`: > > + > > + - ``V4L2_BUF_FLAG_OUT_FENCE`` > > + - 0x00400000 > > + - Request a fence to be attached to the buffer. The ``fence_fd`` > > + field on > > + :ref:`VIDIOC_QBUF` is used as a return argument to send the out-fence > > + fd to userspace. > > > > > > > > diff --git a/drivers/media/usb/cpia2/cpia2_v4l.c b/drivers/media/usb/cpia2/cpia2_v4l.c > > index a1c59f19cf2d..7d7459fa2077 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->fence_fd = -1; > > 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 821f2aa299ae..3a31d318df2a 100644 > > --- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c > > +++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c > > @@ -370,7 +370,7 @@ struct v4l2_buffer32 { > > __s32 fd; > > } m; > > __u32 length; > > - __u32 reserved2; > > + __s32 fence_fd; > > __u32 reserved; > > }; > > > > @@ -533,7 +533,7 @@ static int put_v4l2_buffer32(struct v4l2_buffer *kp, struct v4l2_buffer32 __user > > put_user(kp->timestamp.tv_usec, &up->timestamp.tv_usec) || > > copy_to_user(&up->timecode, &kp->timecode, sizeof(struct v4l2_timecode)) || > > put_user(kp->sequence, &up->sequence) || > > - put_user(kp->reserved2, &up->reserved2) || > > + put_user(kp->fence_fd, &up->fence_fd) || > > put_user(kp->reserved, &up->reserved) || > > put_user(kp->length, &up->length)) > > return -EFAULT; > > diff --git a/drivers/media/v4l2-core/videobuf2-v4l2.c b/drivers/media/v4l2-core/videobuf2-v4l2.c > > index 4075314a6989..4a5244ee2c58 100644 > > --- a/drivers/media/v4l2-core/videobuf2-v4l2.c > > +++ b/drivers/media/v4l2-core/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->fence_fd = -1; > > The patch itself looks ok. I'm just in doubt here, but it is probably > ok to change its default to -1. Right. What we can do is return 0 if the OUT_FENCE flag is not set. Gustavo