How is dmaengine_prep_slave_single supposed to be used?
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
Quoted 6 lines · Lars-Peter Clausen
Hi,
I've tried using
dmaengine_prep_slave_singlein one of my drivers an run into an issue, thedma_addressattribute of the sg element is not initialized and thus the dma transfer and the DMA transfer fails.
Quoted 9 lines
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?
Yes this is broken now, I will fix this up
Signature · 1 line
~Vinod