Re: [PATCH v2 00/10] arm64: tegra: Prevent early SMMU faults

From: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
To: Thierry Reding <thierry.reding@gmail.com>, Will Deacon <will@kernel.org>
Cc: Joerg Roedel <joro@8bytes.org>,
	iommu@lists.linux-foundation.org,
	Jon Hunter <jonathanh@nvidia.com>,
	Nicolin Chen <nicolinc@nvidia.com>,
	linux-tegra@vger.kernel.org, Robin Murphy <robin.murphy@arm.com>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2 00/10] arm64: tegra: Prevent early SMMU faults
Date: Wed, 2 Jun 2021 16:58:10 +0200	[thread overview]
Message-ID: <cc37b000-74f9-696a-e7f6-964b8f948743@canonical.com> (raw)
In-Reply-To: <YLeclZlP8l3dMX4o@orome.fritz.box>

On 02/06/2021 16:58, Thierry Reding wrote:
> On Wed, Jun 02, 2021 at 12:40:49PM +0100, Will Deacon wrote:
>> On Wed, Jun 02, 2021 at 12:44:58PM +0200, Krzysztof Kozlowski wrote:
>>> On 02/06/2021 10:52, Thierry Reding wrote:
>>>> On Wed, Jun 02, 2021 at 09:35:13AM +0200, Krzysztof Kozlowski wrote:
>>>>> On 02/06/2021 09:33, Krzysztof Kozlowski wrote:
>>>>>> On 01/06/2021 20:08, Thierry Reding wrote:
>>>>>>> On Tue, Jun 01, 2021 at 01:26:46PM +0100, Will Deacon wrote:
>>>>>>>> On Fri, May 28, 2021 at 07:05:28PM +0200, Thierry Reding wrote:
>>>>>>>>> On Tue, Apr 20, 2021 at 07:26:09PM +0200, Thierry Reding wrote:
>>>>>>>>>> From: Thierry Reding <treding@nvidia.com>
>>>>>>>>>>
>>>>>>>> Probably best if I queue 3-6 on a separate branch once you send a v3,
>>>>>>>> then Krzysztof can pull that in if he needs it.
>>>>>>>
>>>>>>> Patch 5 has a build-time dependency on patch 1, so they need to go in
>>>>>>> together. The reason why I suggested Krzysztof pick these up is because
>>>>>>> there is a restructuring series that this depends on, which will go into
>>>>>>> Krzysztof's tree. So in order to pull in 3-6, you'd get a bunch of other
>>>>>>> and mostly unrelated stuff as well.
>>>>>>
>>>>>> I missed that part... what other series are needed for this one? Except
>>>>>> Dmitry's power management set I do not have anything in my sight for
>>>>>> Tegras memory controllers.
>>>>>>
>>>>>> Anyway, I can take the memory bits and provide a stable tag with these.
>>>>>> Recently there was quite a lot work around Tegra memory controllers, so
>>>>>> this makes especially sense if new patches appear.
>>>>>
>>>>> OK, I think I have now the patchset you talked about - "memory: tegra:
>>>>> Driver unification" v2, right?
>>>>
>>>> Yes, that's the one. That series is fairly self-contained, but Dmitry's
>>>> power management set has dependencies that pull in the regulator, clock
>>>> and ARM SoC trees.
>>>>
>>>> I did a test merge of the driver unification series with a branch that
>>>> has Dmitry's patches and all the dependencies and there are no conflicts
>>>> so that, fortunately, doesn't further complicates things.
>>>>
>>>> Do you want me to send you a pull request with Dmitry's memory
>>>> controller changes? You could then apply the unification series on top,
>>>> which should allow this SMMU series to apply cleanly on top of that.
>>>
>>> Makes sense and it looks quite bulletproof for future changes. Let's do
>>> like this. I will apply your patch 1/10 from this v2 on top of it and
>>> driver unification later.
>>
>> Okey doke. Thierry -- please let me know which patches I can queue. Having
>> the SMMU driver changes in the IOMMU tree really helps in case of conflicts
>> with other SMMU changes. As I say, I can put stuff on a separate branch for
>> you if it helps.
> 
> Given that the SMMU patches have a build-time dependency on the first
> patch in the series, and the series depends on the unification series, I
> think Krzysztof would have to pull the memory controller branch that I
> have with Dmitry's work, apply the unification series on top and then
> take patch 1 of this series on top of that. That's the state that you'd
> have to pull into the SMMU tree to get the right dependencies.
> 
> The SMMU pieces are the leaf of the dependency tree, so technically no
> separate branch is needed, because I don't think anybody would have to
> pull from it. However, a separate branch might make it easier to back
> any of this work out if we have to.
> 
> Krzysztof, I do plan on sending out a v3 of the unification series to
> address the two cleanups that Dmitry and you have pointed out. After
> that I can send out v3 of this series to fix the ordering issue that
> Krishna had mentioned. After all of those are applied, would you be able
> to provide a stable branch for Will's SMMU tree?

Yes, I will provide a stable branch/tag.

Best regards,
Krzysztof

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