Hi Shuah, Mauro,
I noticed that the function vb2_core_streamon() in videobuf2-core.c calls
v4l_vb2q_enable_media_source(q).
That function in turn assumes that q->owner is a v4l2_fh struct. But I
don't think that is true for DVB devices.
And since videobuf2-core.c is expected to be DVB/V4L independent, this seems
wrong.
It was introduced over 2 years ago in commit 77fa4e0729987:
commit 77fa4e072998705883c4dc672963b4bf7483cea9
Author: Shuah Khan <shuahkh@xxxxxxxxxxxxxxx>
Date: Thu Feb 11 21:41:29 2016 -0200
[media] media: Change v4l-core to check if source is free
Change s_input, s_fmt, s_tuner, s_frequency, querystd, s_hw_freq_seek,
and vb2_core_streamon interfaces that alter the tuner configuration to
check if it is free, by calling v4l_enable_media_source().
If source isn't free, return -EBUSY.
v4l_disable_media_source() is called from v4l2_fh_exit() to release
tuner (source).
vb2_core_streamon() uses v4l_vb2q_enable_media_source().
Signed-off-by: Shuah Khan <shuahkh@xxxxxxxxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxx>
Note that this precedes the DVB_MMAP config option, so at the time this
likely worked fine. But I wonder why it works if that DVB_MMAP option is
set? Pure luck?
I think this call should be moved to videobuf2-v4l2.c (might require some
refactoring). It really doesn't belong in videobuf2-core.c.
Regards,
Hans
