From: "Илья Кузнецов" <ilya@yadro.com>
To: <linuxppc-dev@lists.ozlabs.org>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: a.fomichev@yadro.com
Subject: Re: DMA & POWER8
Date: Fri, 1 Mar 2019 13:32:46 +0300 [thread overview]
Message-ID: <20190301103246.a6elk7ohpmabqyn7@yadro.com> (raw)
In-Reply-To: <20190227155702.ngm3l5bjsde2vvrw@yadro.com>
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@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?
prev parent reply other threads:[~2019-03-01 10:34 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-27 15:57 DMA & POWER8 Илья Кузнецов
2019-03-01 10:32 ` Илья Кузнецов [this message]
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