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Stuck at __vb2_wait_for_done_vb when using yavta to do capture

Question asked by Benson Huang on Apr 12, 2018
Latest reply on Jul 3, 2018 by dh29



We are using i.MX8M to develop i.MX8M MIPI CSI-2 video capture device.

In i.MX8M platform, there are two components which are related to MIPI CSI-2.

One is mx6s_capture (csi1_bridge) and the other is mxc-mipi-csi2_yav (mipi_csi_1).

Our current environment setting of MIPI CSI-2 is 1 data lane, 1 channel and 1 analog camera.

When we use yavta to test the function flow of V4L2, we will be stuck at __vb2_wait_for_done_vb.

Our command: yavta -fUYVY -s720x480 -n4 --capture=5 /dev/video0

After analyzing the log, we found that mx6s_vidioc_dqbuf is not returned and mx6s_csi_irq_handler is not triggered.

It seems maybe DMA transfer is not complete or some other reasons.

Could anyone help to provide some clues or guide us how to debug the issues (e.g. check the register status, buffer content...)?