Hi,
I am working with i.MX8MM EVK and 4.19.35.1.1.0 Yocto distribution.
We have interfaced a slave to ECSPI2 pins exposed on J1003 of i.MX8MM EVK.
ECSPI2 is configured as Master, CPOL = CPHA = 0, Bits Per Word = 8
If SPI burst < 32 bytes PIO mode transfer
If SPI burst >= 32 bytes DMA mode transfer is programmed in spi-imx.c platform driver.
PIO mode works well for SPI burst of 8,16 and 24 bytes (multiple of 8 bytes)
But when we try to use DMA transfer for SPI burst size of 32 / 64 bytes, SPI transfer fails.
After looking at the platform driver code spi-imx.c, I think some piece of code / patch is missing for DMA transfer to work.
Could you please let me know your comments and possible direction for solving this issue.
Thank you, Sreedhar
