From mboxrd@z Thu Jan 1 00:00:00 1970 From: will.deacon@arm.com (Will Deacon) Date: Fri, 5 Jun 2015 10:05:34 +0100 Subject: Master-aware devices and sideband ID data In-Reply-To: <158EFC9F-FCAF-44D3-AD40-804EDFE0CE25@caviumnetworks.com> References: <20150324155007.GC23005@leverpostej> <26BE36EF-2C5B-4DA6-8950-8FEBB031ED1B@caviumnetworks.com> <20150527173953.GC23176@leverpostej> <20150601102208.GD22406@leverpostej> <158EFC9F-FCAF-44D3-AD40-804EDFE0CE25@caviumnetworks.com> Message-ID: <20150605090534.GC1198@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Jun 04, 2015 at 11:19:30PM +0100, Chalamarla, Tirumalesh wrote: > > On Jun 1, 2015, at 3:22 AM, Mark Rutland wrote: > > It's possible to specify that the paths exist. I expect that software > > would select which to use at runtime. > > > My worry is how to define any priorities/preferences between masters. > in general the proposal looks reasonable. I agree that the proposal looks reasonable (in terms of the ability to describe the sort of topologies that we will face) but I still don't understand what I need to do in e.g. my IOMMU driver to support this binding whilst continuing to support the existing iommus binding, which is relied upon to configure dma-mapping. Mark: how do you see this co-existing/merging with the current bindings? I don't think it's practical to throw away what we have and move over to something totally different all in one go, but there clearly *is* benefit in your proposal over the existing scheme. Will