DMA & POWER8

[Илья Кузнецов]

I'm sorry for previous email content without greeting.

A bit more description… We are working on enabling RDMA over PCIe NTB on
OpenPOWER using https://github.com/ntrdma project. During initialization 
dma_request_channel() founds no available channels. We also found that there no 
channels at all in dma_device_list. This is probably powerpc specific problem.
Could someone explain if that is hardware limitation or arch specific part
should be changed?

Ben, a while ago you answered regarding DMA master on POWER8, may be you have 
idea here also?

Thank you in advance!

Илья Кузнецов <ilya at yadro.com> wrote on Ср [2019-фев-27 18:57:02 +0300]:
>We're trying to use Slave-DMA API of the DMA Engine in the linux kernel on
>POWER8 OpenPOWER platform. And we discovered that dma_request_channel() always fails.
>Does it mean that Turismo hardware does not support Slave-DMA? Or DMA
>subsystem in the linux kernel needs to be fixed, doesn't it?