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From: will.deacon@arm•com (Will Deacon)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v3 2/9] iommu/of: Consolidate device creation workarounds
Date: Fri, 1 Jul 2016 13:29:55 +0100	[thread overview]
Message-ID: <20160701122955.GI12735@arm.com> (raw)
In-Reply-To: <577651D7.4030309@arm.com>

On Fri, Jul 01, 2016 at 12:19:51PM +0100, Robin Murphy wrote:
> On 01/07/16 11:32, Marek Szyprowski wrote:
> > Frankly, I would avoid moving this workaround to the iommu core. IMHO the
> > best solution would be to let IOMMU controllers to be instantiated as
> > normal
> > devices and implement proper support in the device core for waiting for the
> > iommu controller. Then the workaround can be removed from exynos and mtk
> > iommu drivers. What's the status of IOMMU deferred probe patches?
> 
> I think revisiting probe ordering is now second-from-top on my to-do
> list after this lot. This patch was kind of thinking ahead to get the
> "touch all the drivers" aspect out of the way before it grows any
> bigger, and all the development can then happen in the core code alone,
> but I admit it's not a particularly strong argument.
> 
> > I've encountered a serious problems with current code (the one which
> > instantiates iommu controller devices from iommu driver) and its
> > integration
> > with power domains, clocks and runtime pm, which were not possible to
> > resolve
> > without iommu deferred probe.
> 
> OK. Do you have any plans to try tweaking the current workaround, or is
> it really not worth it? FWIW I do have an Exynos 5410 (Odroid-XU) on my
> desk which I could theoretically test things on, but I suspect it would
> take a fair amount of work to get the SYSMMUs and relevant media bits up
> and running on top of Krzysztof's basic support.
> 
> Will: for the time being, the alternative to this patch would be to
> squash the following change into patch 7/9 (without either, patch 8/9
> doesn't really work).

It's ugly, but I'm fine with it for the moment. No need to wait for the
probe deferral stuff before getting this in.

Will

  parent reply	other threads:[~2016-07-01 12:29 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-28 15:48 [PATCH v3 0/9] Generic DT bindings for PCI IOMMUs and ARM SMMUv3 Robin Murphy
2016-06-28 15:48 ` [PATCH v3 1/9] arm64: mm: change IOMMU notifier action to attach DMA ops Robin Murphy
2016-06-28 15:48 ` [PATCH v3 2/9] iommu/of: Consolidate device creation workarounds Robin Murphy
2016-07-01 10:22   ` Will Deacon
2016-07-01 10:32   ` Marek Szyprowski
2016-07-01 11:19     ` Robin Murphy
2016-07-01 12:02       ` Marek Szyprowski
2016-07-01 12:29       ` Will Deacon [this message]
2016-06-28 15:48 ` [PATCH v3 3/9] Docs: dt: add PCI IOMMU map bindings Robin Murphy
2016-06-28 15:48 ` [PATCH v3 4/9] of/irq: Break out msi-map lookup (again) Robin Murphy
2016-06-28 15:48 ` [PATCH v3 5/9] iommu/of: Handle iommu-map property for PCI Robin Murphy
2016-07-01 10:31   ` Will Deacon
2016-07-01 11:33     ` Robin Murphy
2016-06-28 15:48 ` [PATCH v3 6/9] iommu/of: Introduce iommu_fwspec Robin Murphy
2016-07-01 10:55   ` Will Deacon
2016-07-01 12:04     ` Robin Murphy
2016-07-07 16:51       ` Lorenzo Pieralisi
2016-06-28 15:48 ` [PATCH v3 7/9] iommu/arm-smmu: Implement of_xlate() for SMMUv3 Robin Murphy
2016-07-01 12:35   ` Will Deacon
2016-07-01 13:26     ` Robin Murphy
2016-06-28 15:48 ` [PATCH v3 8/9] iommu/arm-smmu: Support non-PCI devices with SMMUv3 Robin Murphy
2016-07-01 12:40   ` Will Deacon
2016-07-01 13:05     ` Robin Murphy
2016-06-28 15:48 ` [PATCH v3 9/9] iommu/arm-smmu: Set PRIVCFG in stage 1 STEs Robin Murphy
2016-06-28 16:18 ` [RFC 1/2] iommu/dma: Restrict IOVAs to physical memory layout Robin Murphy
     [not found]   ` <CALRxmdCuxLPogPTwpn2-B=PU=Ry0eNtgs2z+iZBPYtDc3NX-hQ@mail.gmail.com>
2016-07-01 16:03     ` Stuart Yoder
2016-07-01 16:15       ` Robin Murphy
2016-07-01 17:39         ` Robin Murphy
2016-07-01 18:53           ` Stuart Yoder
2016-06-28 16:18 ` [RFC 2/2] iommu/dma: Identity-map non-RAM regions Robin Murphy

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