On 07/06/2023 04:10, Deborah Brouwer wrote:
> When the streaming option is called with a stateful decoder,
> testUserPtr() and testDmaBuf() will hang indefinitely when attempting to
> dequeue a source change event. To prevent this call select() with a
> timeout.
>
> Signed-off-by: Deborah Brouwer <deborah.brouwer@xxxxxxxxxxxxx>
> ---
> It looks like this was the same issue that was previously fixed for testMmap()
> in commit f0a5b17d9 ("v4l2-compliance: add timeout when waiting for event").
>
> utils/v4l2-compliance/v4l2-test-buffers.cpp | 18 ++++++++++++++++++
> 1 file changed, 18 insertions(+)
>
> diff --git a/utils/v4l2-compliance/v4l2-test-buffers.cpp b/utils/v4l2-compliance/v4l2-test-buffers.cpp
> index a097a0ff..0396e17e 100644
> --- a/utils/v4l2-compliance/v4l2-test-buffers.cpp
> +++ b/utils/v4l2-compliance/v4l2-test-buffers.cpp
> @@ -1746,8 +1746,17 @@ int testUserPtr(struct node *node, struct node *node_m2m_cap, unsigned frame_cou
>
> if (node->is_m2m) {
> if (node->codec_mask & STATEFUL_DECODER) {
> + int fd_flags = fcntl(node->g_fd(), F_GETFL);
> + struct timeval tv = { 1, 0 };
> + fd_set efds;
> v4l2_event ev;
>
> + fcntl(node->g_fd(), F_SETFL, fd_flags | O_NONBLOCK);
> + FD_ZERO(&efds);
> + FD_SET(node->g_fd(), &efds);
> + ret = select(node->g_fd() + 1, nullptr, nullptr, &efds, &tv);
> + fail_on_test_val(ret < 0, ret);
> + fail_on_test(ret == 0);
> fail_on_test(node->dqevent(ev));
This code keeps the fd in non-blocking mode. You need to add a
fcntl(node->g_fd(), F_SETFL, fd_flags) line here. See also testMmap().
> fail_on_test(ev.type != V4L2_EVENT_SOURCE_CHANGE);
> fail_on_test(!(ev.u.src_change.changes & V4L2_EVENT_SRC_CH_RESOLUTION));
> @@ -1949,8 +1958,17 @@ int testDmaBuf(struct node *expbuf_node, struct node *node, struct node *node_m2
>
> if (node->is_m2m) {
> if (node->codec_mask & STATEFUL_DECODER) {
> + int fd_flags = fcntl(node->g_fd(), F_GETFL);
> + struct timeval tv = { 1, 0 };
> + fd_set efds;
> v4l2_event ev;
>
> + fcntl(node->g_fd(), F_SETFL, fd_flags | O_NONBLOCK);
> + FD_ZERO(&efds);
> + FD_SET(node->g_fd(), &efds);
> + ret = select(node->g_fd() + 1, nullptr, nullptr, &efds, &tv);
> + fail_on_test_val(ret < 0, ret);
> + fail_on_test(ret == 0);
> fail_on_test(node->dqevent(ev));
Ditto.
> fail_on_test(ev.type != V4L2_EVENT_SOURCE_CHANGE);
> fail_on_test(!(ev.u.src_change.changes & V4L2_EVENT_SRC_CH_RESOLUTION));
Regards,
Hans
