topic V4L2_MEMORY_USERPTR in i.MX Processors

V4L2_MEMORY_USERPTR

ashokp — Fri, 03 Jun 2016 12:26:11 GMT

We are working on the custom IMX6 board. Below are the details.

Processor: iMX6 (Quad)

Interface: MIPI CSI-2

Camera: any MIPI CSI-2 based camera sensor

We are passing the buffer from user program to V4l2 using the userptr

For the Linux iMX6, v4l2 support,

Whether the V4L2_MEMORY_USERPTR is been supported?
If so, which kernel version is tested for this feature? Can you provide the link/reference?
Any tested/example code for iMX6 platform?

Thanks,

P.Ashok

Re: V4L2_MEMORY_USERPTR

Yuri — Mon, 06 Jun 2016 02:58:44 GMT

Hello,

the following may be helpful V4L2_MEMORY_USERPTR example for iMX6

Have a great day,
Yuri

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Re: V4L2_MEMORY_USERPTR

ashokp — Thu, 09 Jun 2016 10:59:48 GMT

Thanks for your reply. As per the thread, the userptr is only supported for physically contiguous memory. My question is whether iMX6 supports dis-contiguous userptr as well? Meaning, whether iMX6 can receive the streaming data from camera in memory that is discontiguous? If yes, can you point the relevant section in the iMX6 datasheet?

Re: V4L2_MEMORY_USERPTR

Yuri — Thu, 16 Jun 2016 02:31:18 GMT

Hello,

I think - from performance perspective - it would be better to increase continuous

(DMA) space, say, using "cma=" kernel boot parameter.

Regards,

Yuri.