linux-kernel - Re: [PATCH 1/4] interconnect: qcom: x1e80100: Remove bogus per-RSC BCMs and nodes

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Message-ID: <2aa360c6-3e8a-4454-8a1e-31ed285d7a68@linaro.org>
Date: Thu, 4 Jan 2024 11:06:05 +0100
From: Konrad Dybcio <konrad.dybcio@...aro.org>
To: Rajendra Nayak <quic_rjendra@...cinc.com>,
 Bjorn Andersson <andersson@...nel.org>, Georgi Djakov <djakov@...nel.org>,
 Rob Herring <robh+dt@...nel.org>,
 Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
 Conor Dooley <conor+dt@...nel.org>, Sibi Sankar <quic_sibis@...cinc.com>,
 Abel Vesa <abel.vesa@...aro.org>
Cc: Marijn Suijten <marijn.suijten@...ainline.org>,
 linux-arm-msm@...r.kernel.org, linux-pm@...r.kernel.org,
 linux-kernel@...r.kernel.org, devicetree@...r.kernel.org
Subject: Re: [PATCH 1/4] interconnect: qcom: x1e80100: Remove bogus per-RSC
 BCMs and nodes

On 4.01.2024 10:59, Rajendra Nayak wrote:
> 
> 
> On 1/2/2024 11:59 PM, Konrad Dybcio wrote:
>> The downstream kernel has infrastructure for passing votes from different
>> interconnect nodes onto different RPMh RSCs. This neither implemented, not
>> is going to be implemented upstream (in favor of a different solution
>> using ICC tags through the same node).
>>
>> Unfortunately, as it happens, meaningless (in the upstream context) parts
>> of the vendor driver were copied, ending up causing havoc - since all
>> "per-RSC" (in quotes because they all point to the main APPS one) BCMs
>> defined within the driver overwrite the value in RPMh on every
>> aggregation.
>>
>> To both avoid keeping bogus code around and possibly introducing
>> impossible-to-track-down bugs (busses shutting down for no reason), get
>> rid of the duplicated BCMs and their associated ICC nodes.
> 
> Thanks Konrad for catching this, I do see these nodes in other Qualcomm SoCs upstream (atleast sm8350/sm8450 and sm8550), perhaps they need to be cleaned up as well?
Yes, I cleaned up 8550 last week, I'll look into the rest.

Konrad