From: Jason Gunthorpe <jgg@ziepe.ca>
To: Konrad Dybcio <konradybcio@gmail.com>
Cc: Krzysztof Kozlowski <krzk@kernel.org>,
Vishnu Reddy <busanna.reddy@oss.qualcomm.com>,
Rob Herring <robh@kernel.org>,
Krzysztof Kozlowski <krzk+dt@kernel.org>,
Conor Dooley <conor+dt@kernel.org>,
devicetree@vger.kernel.org,
Vikash Garodia <vikash.garodia@oss.qualcomm.com>,
Robin Murphy <robin.murphy@arm.com>,
joro@8bytes.org, will@kernel.org, m.szyprowski@samsung.com,
iommu@lists.linux.dev, linux-kernel@vger.kernel.org,
dikshita.agarwal@oss.qualcomm.com,
Bjorn Andersson <bjorn.andersson@oss.qualcomm.com>,
Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>,
Robin Clark <robclark@qti.qualcomm.com>,
Akhil P Oommen <akhilpo@oss.qualcomm.com>,
Srinivas Kandagatla <srinivas.kandagatla@oss.qualcomm.com>,
Ekansh Gupta <ekansh.gupta@oss.qualcomm.com>,
Loic Poulain <loic.poulain@oss.qualcomm.com>
Subject: Re: [PATCH] dma-iommu: Introduce API to reserve IOVA regions for dynamically created devices
Date: Fri, 17 Jul 2026 13:07:16 -0300 [thread overview]
Message-ID: <20260717160716.GA701389@ziepe.ca> (raw)
In-Reply-To: <dba037fa-0f21-4a50-8727-076a3b177c47@gmail.com>
On Fri, Jul 17, 2026 at 12:44:54PM +0200, Konrad Dybcio wrote:
> I was kinda hoping there would be more buy-in to follow what PCIe
> does, but to my understanding you're opposed to it because "vpu_bus"
> is not dynamically discoverable.
PCIe allows describing devices in DT. What this weird vpu_bus thing
seems to be about is to actively avoid describing the devices in DT
while simultaenously treating them like devices. I think it makes no
sense..
IMHO the approach inverts the thing, you start the main driver then
use vpu_bus to dynamically create a bunch of struct device DMA handles
for the main driver to use.
I think it is much better if you start the main driver, use the new
component stuff:
https://docs.kernel.org/driver-api/component.html
To aggregate a driver from the struct device DMA handles that DT will
create automatically. ie the reversed flow, the struct devices
pre-exist created by DT instead of being created by code in your
driver.
Jason
prev parent reply other threads:[~2026-07-17 16:07 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-19 5:49 Vishnu Reddy
2026-01-19 8:00 ` Christoph Hellwig
2026-01-19 14:13 ` Robin Murphy
2026-06-10 14:27 ` Vishnu Reddy
2026-06-12 17:26 ` Jason Gunthorpe
2026-06-15 6:56 ` Vikash Garodia
2026-06-15 12:52 ` Jason Gunthorpe
2026-06-15 17:51 ` Vishnu Reddy
2026-06-17 19:40 ` Jason Gunthorpe
2026-06-18 11:57 ` Krzysztof Kozlowski
2026-06-18 15:17 ` Jason Gunthorpe
2026-06-24 10:16 ` Krzysztof Kozlowski
2026-07-17 10:44 ` Konrad Dybcio
2026-07-17 12:21 ` Robin Murphy
2026-07-17 16:07 ` Jason Gunthorpe [this message]
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