8M Plus Save Raw Data Buffer Overflow Problem

[MengG]

I compiled a system that supports both uvc and v4l2 using the Summit SOM 8M Plus DVK provided by our customer. Now connect our USB 3.0 module (ar1335) through the USB 3.0 interface. The resolution of the module is 4208x3120. We can obtain the raw data stream through v4l2. The command is as follows.

v4l2-ctl --stream-mmap -d0

However, if we save raw locally, the v4l2 command may encounter a buffer overflow problem. The command is as follows.

v4l2-ctl --set-fmt-video=width=4208,height=3120 --stream-mmap --stream-count=10 --stream-to=ar1335.raw -d /dev/video0

I would like to ask if the system configuration of IMx8 has caused caching to fail at such a large resolution. Do you have any suggestions?

[joanxie]

what bsp version do you use? did you use the third party company board? could you share detailed information about your board and your bsp?

[MengG]

Hi joanxie,

I use the development board provided by the customer, and refer to the following link to compile the system and image.

Getting Started | Laird Connectivity - GitHub Documentation (lairdcp.github.io)

Developing a custom image with Yocto | Laird Connectivity - GitHub Documentation (lairdcp.github.io)

I am using Linux 5.10.72BSP.

Attached is the system startup log.

[joanxie]

this is the third company board and bsp, I checked the nxp board,

[ 0.000000] Reserved memory: created CMA memory pool at 0x00000000c4000000, size 960 MiB
[ 0.000000] OF: reserved mem: initialized node linux,cma, compatible id shared-dma-pool
[ 0.000000] Reserved memory: created DMA memory pool at 0x0000000094300000, size 1 MiB
[ 0.000000] OF: reserved mem: initialized node vdev0buffer@94300000, compatible id shared-dma-pool
[ 0.000000] NUMA: No NUMA configuration found

you can check the dts file

"https://source.codeaurora.org/external/imx/linux-imx/tree/arch/arm64/boot/dts/freescale/imx8mp.dtsi?...

find the "linux,cma "

[MengG]

Hi joanxie,

Could you give me more details about the issue with the CMA?

[joanxie]

you can refer to the nxp bsp about cma settings, then try to change it to check if your issue fix or not, but I don't know what DDR your board use, you need contact the third party company to give you more further help