Hikey960 with kernel 4.9 on spi (SPI2 and SPI3) is giving read error on higher frequency(20MHz)

96boards

#1

Hikey960 with kernel 4.9 on spi (SPI2(LS) and SPI3(HS)) is giving read error on higher frequency(20MHz). Has anyone tried it out prior ? Any help appreciated.

Read is completely unsuccessful, never worked on higher frequency. But on kernel 4.4 when we had tried last time it was working good on 20 MHz.


#2

spi_read is returning 0 but no data. @Loic @guodong Any clue. Let me know if you need more information. I have tested the slave device on another host platform and it was running at 20MHz.


#3

Is your question related to https://bugs.96boards.org/show_bug.cgi?id=555
?

-Guodong


#4

I can check by enabling dma support in SPI3 node on HS. Which dmaX shall I use for SPI3 ? dma0/dma1… ?


#5

For SPI3, RX 12, TX 13, use these channels.


#6

DMA seems to be enabled. When I try with 19.2MHz, in CRO it reads 13.4MHz. I have to get this SPI interface up with ~20MHz. Can anyone shed some light ? @guodong @Loic