Hello All,
Will appreciate if someone can clear my doubts regarding XOR/GF
offload for raid5/6.
1) What is the purpose of device_prep_dma_interrupt callback ?
2) My driver currently polls for checking the xor completions
and does'nt implement device_prep_dma_interrupt
callback at all. What performance variation I can expect by
implementing this callback
in my async_tx driver.
3) Purpose of DMA_ACK as I read - it is for higher layers to inform
dma driver that descriptors can now be freed. Can someone explain this
with an example as applicable with raid5/6 clients.
4) With example - why dma_run_dependencies(tx) needed after the
hardware engine posts completion for a descriptor.
5) Purpose of tx->callback(cb_arg) - again with an example from a
raid5/6 offload perspective.
Goal: I want to use offload engine efficiently with recent
multithreaded raid5/6.
I tried to dig through code and linux/Documentation etc but not
thoroughly clear of functionality.
Thanks & Regards
Vikas Aggarwal