Re: [PATCH v6 01/16] arm64: dts: qcom: kodiak: Add EL2 overlay

[Sumit Garg <sumit.garg@kernel.org>]

On Tue, May 19, 2026 at 07:33:45AM +0000, sashiko-bot@kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
> - [High] The `kodiak-el2.dtso` overlay omits the `iommus` configuration for the `remoteproc_mpss` (modem) node.
> - [Medium] The commit message fails to explain why `gpu_zap_shader` and `venus` are disabled, and why `watchdog` is enabled in the EL2 overlay.
> --
> 
> commit b4ab2188dfbc3caab6111f1ec38bf830bc7a5ef3
> Author: Mukesh Ojha <mukesh.ojha@oss.qualcomm.com>
> 
> arm64: dts: qcom: kodiak: Add EL2 overlay
> 
> This commit adds an EL2-specific DT overlay for Kodiak devices to boot
> without the Gunyah hypervisor. It configures the remote processor firmware
> IOMMU streams to be managed by the consumer rather than the hypervisor.
> 
> Link: https://docs.qualcomm.com/bundle/publicresource/topics/80-70020-4/boot-developer-touchpoints.html#uefi
> 
> > When running under Gunyah, the remote processor firmware IOMMU
> > streams are controlled by Gunyah. However, without Gunyah, the IOMMU is
> > managed by the consumer of this DeviceTree. Therefore, describe the
> > firmware streams for each remote processor.
> >
> > Add a EL2-specific DT overlay and apply it to Kodiak IOT variant
> > devices to create -el2.dtb for each of them alongside "normal" dtb.
> >
> > [1]
> > https://docs.qualcomm.com/bundle/publicresource/topics/80-70020-4/boot-developer-touchpoints.html#uefi
> >
> > Signed-off-by: Mukesh Ojha <mukesh.ojha@oss.qualcomm.com>
> > [SG: watchdog fixup]
> > Signed-off-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
> 
> This isn't a bug, but the commit message focuses solely on the IOMMU
> stream configurations. Could the message be updated to explain the
> rationale behind disabling the gpu_zap_shader and venus nodes, as well
> as enabling the watchdog?
> 
> > diff --git a/arch/arm64/boot/dts/qcom/kodiak-el2.dtso b/arch/arm64/boot/dts/qcom/kodiak-el2.dtso
> > new file mode 100644
> > index 0000000000000..0b3a69a0d7654
> > --- /dev/null
> > +++ b/arch/arm64/boot/dts/qcom/kodiak-el2.dtso
> > @@ -0,0 +1,35 @@
> > +// SPDX-License-Identifier: BSD-3-Clause
> 
> [ ... ]
> 
> > +&remoteproc_adsp {
> > +	iommus = <&apps_smmu 0x1800 0x0>;
> > +};
> > +
> > +&remoteproc_cdsp {
> > +	iommus = <&apps_smmu 0x11a0 0x0400>;
> > +};
> > +
> > +&remoteproc_wpss {
> > +	iommus = <&apps_smmu 0x1c03 0x1>,
> > +		 <&apps_smmu 0x1c83 0x1>;
> > +};
> 
> Is there a missing remoteproc_mpss node here?
> 
> The qcs6490-rb3gen2.dts board file enables remoteproc_mpss and
> configures it to load modem.mbn.
> 
> Since the MPSS streams are routed through the APPS SMMU on Kodiak devices,
> will the omission of the iommus property for the modem cause SMMU context
> translation faults and prevent the peripheral from booting?

Nice catch, I will disable remoteproc_mpss for the next revision since
it's currently not tested in EL2 mode.

-Sumit