Data inconsistency observed while performing to-device DMA with spi-nor (m25p80)

AYAN KUMAR HALDER ayankumarh at gmail.com
Sun Jul 26 07:32:03 EDT 2015


Hi,

I am doing a DMA transfer (to device) using pl330 driver from
memory(DDR) to device(m25p80, spi- nor). I am sending data in chunks
of 256 bytes ( m25p80 - writesize) using scatter-gather mechanism.

I see that when I try to write 8K of data, one or the other 256
bytes(or lesser) are not written or are partially written with 0s.

This problem is observed only when I perform a to-device DMA transfer.
When I perform a from-device DMA transfer, I am able to read correct
data.

Regards,
Ayan Kumar Halder



More information about the Kernelnewbies mailing list