STM32MP153 - DCMI only capture 320x240 or smaller

[Dat Tran]

Hi, I am using STM32MP153 and DCMI interface, camera OV5640.

we are using DT same as here: DCMI device tree configuration - stm32mpu

For 640x480 or higher, we always get dma error as below:

For 320x240: Seems first capture has no problem, but start from second capture, we also always have dma error as below:

 

does anyone know what I am missing, please?

 

 

 

[PatrickF]

Hi @Dat Tran 

Maybe AN5470 STM32MP15x Series interfacing with a MIPI® CSI-2 camera could help

Regards.

[Dat Tran]

Thanks PatrickF,

I got dma working with resolution higher than 320x240. Problem was, I am using old kernel that using dmaengine_prep_slave_single while new version use dmaengine_prep_slave_sg.

 

But I still have one more problem if you know or have any hint.

In stm32-dcmi.c we have 

dcmi->dma_max_burst = caps.max_sg_burst * DMA_SLAVE_BUSWIDTH_4_BYTES;

When I debug, this value give me 262080 = 65520 * 4  = STM32_DMA_ALIGNED_MAX_DATA_ITEMS * 4

Any transfer bigger than 262080 bytes will be failed.