How is dmaengine_prep_slave_single supposed to be used?
From: Lars-Peter Clausen
Date: Fri Jan 27 2012 - 09:32:03 EST
Hi,
I've tried using dmaengine_prep_slave_single in one of my drivers an run
into an issue, the dma_address attribute of the sg element is not
initialized and thus the dma transfer and the DMA transfer fails.
Quoting from Documentation/dmaengine.txt:
The peripheral driver is expected to have mapped the scatterlist for
the DMA operation prior to calling device_prep_slave_sg, and must
keep the scatterlist mapped until the DMA operation has completed.
So this is clearly not the case with dmaengine_prep_slave_single, so I'm
wondering how is ut supposed to be used and can it work properly at all?
Thanks,
- Lars
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