Hi all,
So, I've been trying to test the REQBUFS(0) from libv4l2 with my
omap4iss device, and I've hit the following problem:
So, I basically do the basic IOCTL sequence:
open(/dev/video0)
VIDIOC_QUERYCAP
VIDIOC_ENUM_FMT
VIDIOC_ENUM_FRAMESIZES
VIDIOC_ENUM_FRAMEINTERVALS
VIDIOC_S_FMT (w = 640, h = 480, pixfmt = V4L2_PIX_FMT_YUYV, type =
V4L2_BUF_TYPE_VIDEO_CAPTURE)
VIDIOC_S_PARM (capability = V4L2_CAP_TIMEPERFRAME, timeperframe = 1/30)
VIDIOC_REQBUFS (count = 6, MMAP)
Loop for 6 times:
VIDIOC_QUERYBUF (to get buff length)
mmap(length)
Loop for 6 times:
VIDIOC_QBUF(index = 0-5)
VIDIOC_STREAMON
(Loop to poll, DQBUF and QBUF the same buffer)
VIDIOC_STREAMOFF
Loop for 6 times:
munmap()
VIDIOC_REQBUFS (count = 0, MMAP)
... And in this call, it fails on libv4l2 level, since it checks all
buffers to see
if they're mapped, by doign QUERYBUF on each index, and checking for
"V4L2_BUF_FLAG_MAPPED" flag.
Now, digging deep into how this flag is populated, I noticed the following:
I notice that in "drivers/media/video/videobuf2-core.c", inside:
vb2_querybuf()
-> __fill_v4l2_buffer()
There's this condition:
if (vb->num_planes_mapped == vb->num_planes)
b->flags |= V4L2_BUF_FLAG_MAPPED;
The problem is that, even if i did a munmap, the count of vb->num_planes_mapped
is not decreased... :/
How's this supposed to work? Do I need to do something in my driver to avoid
this flag to be set?
Regards,
Sergio
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
