dmaengine: DMA_CTRL_ACK flag signification

From: Nicolas Ferre
Date: Wed Sep 24 2008 - 07:59:36 EST


Hi all,

I am in the process of writing a driver for an on-chip Atmel DMA engine.

I am a little confused about the use of the flag DMA_CTRL_ACK : It seems that it is set in most of the descriptors in use except the first or last of a descriptor chain. So, I cannot find where this flag is cleared.
In short, I do not see what it is used for : how must I take it into account in my driver (in device_prep_dma_memcpy() for instance) ?

Can you enlighten me ?

Regards,
--
Nicolas Ferre

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