When you use read buffers direct for display preview there is not problem because there are not time delay but when you would like to do something else for example compress frame to jpeg you will have some time delay if you do not do it speed enough and then you will miss out some frames.
In that case driver will stuck. If you allocate for example 10 buffers first 9 buffers will has picture from fist filing up and there stuck. Only last buffer will keep going to fill up with correct frame value.
There is patch which should resolve this issue.
@sunxi-tvin/sun7i_tvd-linux-3.4-working/drv_tvd.c
/* Nobody is waiting on this buffer*/
if (!waitqueue_active(&buf->vb.done)) {
__dbg(" Nobody is waiting on this buffer,buf = 0x%p\n",buf);
When you use read buffers direct for display preview there is not problem because there are not time delay but when you would like to do something else for example compress frame to jpeg you will have some time delay if you do not do it speed enough and then you will miss out some frames. In that case driver will stuck. If you allocate for example 10 buffers first 9 buffers will has picture from fist filing up and there stuck. Only last buffer will keep going to fill up with correct frame value. There is patch which should resolve this issue.
@sunxi-tvin/sun7i_tvd-linux-3.4-working/drv_tvd.c
Best regards, Milos