V4L2_MEMORY_USERPTR example for iMX8QM

[aso]

Hello everyone,

I'm programming V4L2  using Linux 4.19.35, on an evaluation board MCIMX8QM-CPU.

The camera uses MX8X MIPI4CAM2.

So the question is, is it possible to use the V4L2_MEMORY_USERPTR feature of V4L2?
Or, if you have a sample source somewhere, please let me know.

Currently, I can capture using V4L2_MEMORY_USERPTR, but when I look at the capture screen, it is black. We are currently investigating at what level the black screen is displayed.

[igorpadykov · Accepted solution]

Hi aso

one can look at unit tests example : V4L2_MEMORY_USERPTR

can be used for i.MX8M, but not with i.MX8QM:

https://source.codeaurora.org/external/imx/imx-test/tree/test/mxc_v4l2_test/mx8_v4l2_cap_drm.c?h=imx...

https://source.codeaurora.org/external/imx/imx-test/tree/test/mxc_v4l2_test/mx6s_v4l2_cap_drm.c?h=im...

Best regards
igor