The original cause seems to be in spi driver. I tested setting enable_dma flag to false in spi-pxa2xx driver and that fixes the problem. Will investigate in spi driver side. Thanks!

Hsin-yu

On Mon, Jul 24, 2017 at 11:06 AM, Oder Chiou oder_chiou@realtek.com wrote:

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On Fri, Jul 21, 2017 at 04:00:47PM +0800, Oder Chiou wrote:

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The patch uses the local variable to get the data from SPI device to prevent to get all zero data.

How do you end up with all zero data from reading directly into rxbuf?

While the "runtime->dma_area" put into the rxbuf directly on the Intel platform, it seemed that had the limitation to let the memory cannot be written the data using the driver of the SPI controller. We verified the original code on the platforms of Nvidia and Rockchip, and these are working fine.