Re: [PATCH v2 6/9] interconnect: qcom: let platforms declare their bugginess

From: Konrad Dybcio

Date: Wed Mar 25 2026 - 07:01:38 EST


On 3/24/26 1:14 PM, Luca Weiss wrote:
> On Tue Mar 24, 2026 at 1:10 AM CET, Dmitry Baryshkov wrote:
>> On MSM8974 programming some of the RPM resources results in the
>> "resource does not exist" messages from the firmware. This occurs even
>> with the downstream bus driver, which happily ignores the errors. My
>> assumption is that these resources existed in the earlier firmware
>> revisions but were later switched to be programmed differently (for the
>> later platforms corresponding nodes use qos.ap_owned, which prevents
>> those resources from being programmed.
>>
>> In preparation for conversion of the MSM8974 driver (which doesn't have
>> QoS code yet) to the main icc-rpm set of helpers, let the driver declare
>> that those -ENXIO errors must be ignored (for now). Later, when the QoS
>> programming is sorted out (and more interconnects are added to the DT),
>> this quirk might be removed.
>
> For reference, these are the errors I see on fairphone-fp2
>
> [ 5.534806] qcom_icc_rpm_smd_send mas 8 error -6
> [ 5.535010] qcom_icc_rpm_smd_send mas 8 error -6
> [ 5.535218] qcom_icc_rpm_smd_send slv 16 error -6
> [ 5.535445] qcom_icc_rpm_smd_send slv 16 error -6

I only checked these two, but 8994 (basically largely reused design
thought) sets them as AP owned intentionally

https://android.googlesource.com/kernel/msm/+/android-msm-angler-3.10-nougat/arch/arm/boot/dts/qcom/msm8994-bus.dtsi

so I suppose the fix is to simply denote all of them as such and go on
with our life!

Konrad