From: Jordan Crouse <jcrouse@codeaurora.org>
To: Konrad Dybcio <konradybcio@gmail.com>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>,
Will Deacon <will@kernel.org>,
skrzynka@konradybcio.pl, Robin Murphy <robin.murphy@arm.com>,
Joerg Roedel <joro@8bytes.org>, Rob Herring <robh+dt@kernel.org>,
linux-arm-kernel@lists.infradead.org,
iommu@lists.linux-foundation.org,
DTML <devicetree@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
John Stultz <john.stultz@linaro.org>
Subject: Re: [PATCH 1/1] iommu/arm-smmu: Implement qcom,skip-init
Date: Tue, 21 Jul 2020 09:44:15 -0600 [thread overview]
Message-ID: <20200721154415.GA5758@jcrouse1-lnx.qualcomm.com> (raw)
In-Reply-To: <CAMS8qEWO-1mNd12Zs-2WogCrgNF5=6RkF=Z1pTeOZxSuKjx+qg@mail.gmail.com>
On Tue, Jul 21, 2020 at 05:04:11PM +0200, Konrad Dybcio wrote:
> So.. is this a no-no?
>
> I of course would like to omit this entirely, but SMMUs on sdm630 and
> friends are REALLY picky.. What seems to happen is that when the
> driver tries to do things the "standard" way, hypervisor decides to
> hang the platform or force a reboot. Not very usable.
>
>
> This thing is needed for the platform to even boot properly and one
> more [1] is required to make mdss work with video mode panels (the
> fact that CMD-mode panels work is kinda hilarious to me).
>
> To be honest, there are even more qcom quirks (of which at least
> qcom,dynamic and qcom-use-3-lvl-tables are used on 630).. [2]
>
> Looking forward to your answers and possibly better solutions.
Nobody is disputing that the qcom SMMUs don't have their share of quirks but it
seems that the community has mostly settled on the agreement that there are
better ways to solve this than a handful of device tree properties. The current
focus has been on moving more of the SMMU specific bits into the arm-smmu-qcom
implementation [1] and I think that is the right way to go.
As for the other quirks we can probably discuss those on a case by case basis.
I doubt you will find much enthusiasm for qcom,use-3-lvl-tables and I've been
working on replacing qcom,dynamic with something much better [2].
[1] https://lists.linuxfoundation.org/pipermail/iommu/2020-July/046304.html
[2] https://lists.linuxfoundation.org/pipermail/iommu/2020-July/046756.html
Jordan
> [1] https://github.com/konradybcio/linux/commit/83ac38af259968f92b6a8b7eab90096c78469f87
> [2] https://github.com/sonyxperiadev/kernel/blob/aosp/LA.UM.7.1.r1/drivers/iommu/arm-smmu.c#L404-L415
>
> Regards
> Konrad
--
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
WARNING: multiple messages have this Message-ID (diff)
From: Jordan Crouse <jcrouse@codeaurora.org>
To: Konrad Dybcio <konradybcio@gmail.com>
Cc: DTML <devicetree@vger.kernel.org>,
skrzynka@konradybcio.pl, Will Deacon <will@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
iommu@lists.linux-foundation.org,
Rob Herring <robh+dt@kernel.org>,
John Stultz <john.stultz@linaro.org>,
Robin Murphy <robin.murphy@arm.com>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 1/1] iommu/arm-smmu: Implement qcom,skip-init
Date: Tue, 21 Jul 2020 09:44:15 -0600 [thread overview]
Message-ID: <20200721154415.GA5758@jcrouse1-lnx.qualcomm.com> (raw)
In-Reply-To: <CAMS8qEWO-1mNd12Zs-2WogCrgNF5=6RkF=Z1pTeOZxSuKjx+qg@mail.gmail.com>
On Tue, Jul 21, 2020 at 05:04:11PM +0200, Konrad Dybcio wrote:
> So.. is this a no-no?
>
> I of course would like to omit this entirely, but SMMUs on sdm630 and
> friends are REALLY picky.. What seems to happen is that when the
> driver tries to do things the "standard" way, hypervisor decides to
> hang the platform or force a reboot. Not very usable.
>
>
> This thing is needed for the platform to even boot properly and one
> more [1] is required to make mdss work with video mode panels (the
> fact that CMD-mode panels work is kinda hilarious to me).
>
> To be honest, there are even more qcom quirks (of which at least
> qcom,dynamic and qcom-use-3-lvl-tables are used on 630).. [2]
>
> Looking forward to your answers and possibly better solutions.
Nobody is disputing that the qcom SMMUs don't have their share of quirks but it
seems that the community has mostly settled on the agreement that there are
better ways to solve this than a handful of device tree properties. The current
focus has been on moving more of the SMMU specific bits into the arm-smmu-qcom
implementation [1] and I think that is the right way to go.
As for the other quirks we can probably discuss those on a case by case basis.
I doubt you will find much enthusiasm for qcom,use-3-lvl-tables and I've been
working on replacing qcom,dynamic with something much better [2].
[1] https://lists.linuxfoundation.org/pipermail/iommu/2020-July/046304.html
[2] https://lists.linuxfoundation.org/pipermail/iommu/2020-July/046756.html
Jordan
> [1] https://github.com/konradybcio/linux/commit/83ac38af259968f92b6a8b7eab90096c78469f87
> [2] https://github.com/sonyxperiadev/kernel/blob/aosp/LA.UM.7.1.r1/drivers/iommu/arm-smmu.c#L404-L415
>
> Regards
> Konrad
--
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
WARNING: multiple messages have this Message-ID (diff)
From: Jordan Crouse <jcrouse@codeaurora.org>
To: Konrad Dybcio <konradybcio@gmail.com>
Cc: DTML <devicetree@vger.kernel.org>,
skrzynka@konradybcio.pl, Will Deacon <will@kernel.org>,
Joerg Roedel <joro@8bytes.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Bjorn Andersson <bjorn.andersson@linaro.org>,
iommu@lists.linux-foundation.org,
Rob Herring <robh+dt@kernel.org>,
John Stultz <john.stultz@linaro.org>,
Robin Murphy <robin.murphy@arm.com>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 1/1] iommu/arm-smmu: Implement qcom,skip-init
Date: Tue, 21 Jul 2020 09:44:15 -0600 [thread overview]
Message-ID: <20200721154415.GA5758@jcrouse1-lnx.qualcomm.com> (raw)
In-Reply-To: <CAMS8qEWO-1mNd12Zs-2WogCrgNF5=6RkF=Z1pTeOZxSuKjx+qg@mail.gmail.com>
On Tue, Jul 21, 2020 at 05:04:11PM +0200, Konrad Dybcio wrote:
> So.. is this a no-no?
>
> I of course would like to omit this entirely, but SMMUs on sdm630 and
> friends are REALLY picky.. What seems to happen is that when the
> driver tries to do things the "standard" way, hypervisor decides to
> hang the platform or force a reboot. Not very usable.
>
>
> This thing is needed for the platform to even boot properly and one
> more [1] is required to make mdss work with video mode panels (the
> fact that CMD-mode panels work is kinda hilarious to me).
>
> To be honest, there are even more qcom quirks (of which at least
> qcom,dynamic and qcom-use-3-lvl-tables are used on 630).. [2]
>
> Looking forward to your answers and possibly better solutions.
Nobody is disputing that the qcom SMMUs don't have their share of quirks but it
seems that the community has mostly settled on the agreement that there are
better ways to solve this than a handful of device tree properties. The current
focus has been on moving more of the SMMU specific bits into the arm-smmu-qcom
implementation [1] and I think that is the right way to go.
As for the other quirks we can probably discuss those on a case by case basis.
I doubt you will find much enthusiasm for qcom,use-3-lvl-tables and I've been
working on replacing qcom,dynamic with something much better [2].
[1] https://lists.linuxfoundation.org/pipermail/iommu/2020-July/046304.html
[2] https://lists.linuxfoundation.org/pipermail/iommu/2020-July/046756.html
Jordan
> [1] https://github.com/konradybcio/linux/commit/83ac38af259968f92b6a8b7eab90096c78469f87
> [2] https://github.com/sonyxperiadev/kernel/blob/aosp/LA.UM.7.1.r1/drivers/iommu/arm-smmu.c#L404-L415
>
> Regards
> Konrad
--
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-07-21 15:44 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-04 12:28 [PATCH 1/1] iommu/arm-smmu: Implement qcom,skip-init Konrad Dybcio
2020-07-04 12:28 ` Konrad Dybcio
2020-07-04 12:28 ` Konrad Dybcio
2020-07-04 13:09 ` Will Deacon
2020-07-04 13:09 ` Will Deacon
2020-07-04 13:09 ` Will Deacon
2020-07-04 13:20 ` Konrad Dybcio
2020-07-04 13:20 ` Konrad Dybcio
2020-07-04 13:20 ` Konrad Dybcio
2020-07-05 3:35 ` Bjorn Andersson
2020-07-05 3:35 ` Bjorn Andersson
2020-07-05 3:35 ` Bjorn Andersson
2020-07-21 15:04 ` Konrad Dybcio
2020-07-21 15:04 ` Konrad Dybcio
2020-07-21 15:04 ` Konrad Dybcio
2020-07-21 15:44 ` Jordan Crouse [this message]
2020-07-21 15:44 ` Jordan Crouse
2020-07-21 15:44 ` Jordan Crouse
2020-07-21 16:20 ` Konrad Dybcio
2020-07-21 16:20 ` Konrad Dybcio
2020-07-21 16:20 ` Konrad Dybcio
2020-07-21 23:56 ` Bjorn Andersson
2020-07-21 23:56 ` Bjorn Andersson
2020-07-21 23:56 ` Bjorn Andersson
2020-07-22 20:11 ` Konrad Dybcio
2020-07-22 20:11 ` Konrad Dybcio
2020-07-22 20:11 ` Konrad Dybcio
2020-07-31 5:48 ` Bjorn Andersson
2020-07-31 5:48 ` Bjorn Andersson
2020-07-31 5:48 ` Bjorn Andersson
2020-08-03 23:57 ` Konrad Dybcio
2020-08-03 23:57 ` Konrad Dybcio
2020-08-03 23:57 ` Konrad Dybcio
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