linux-kernel - Re: [PATCH v3 4/7] arm64: dts: qcom: sc8280xp: Add Venus

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <ecfzllcz2b4h45eymsg4quncu5ec3fqbheufn5wtkbykb6dg3m@k37ocioybgpx>
Date: Mon, 26 Jan 2026 12:47:43 +0200
From: Dmitry Baryshkov <dmitry.baryshkov@....qualcomm.com>
To: Konrad Dybcio <konrad.dybcio@....qualcomm.com>
Cc: Vikash Garodia <vikash.garodia@....qualcomm.com>,
        Dikshita Agarwal <dikshita.agarwal@....qualcomm.com>,
        Bryan O'Donoghue <bod@...nel.org>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        Rob Herring <robh@...nel.org>,
        Krzysztof Kozlowski <krzk+dt@...nel.org>,
        Conor Dooley <conor+dt@...nel.org>,
        Konrad Dybcio <konradybcio@...nel.org>,
        Abhinav Kumar <abhinav.kumar@...ux.dev>,
        Bjorn Andersson <andersson@...nel.org>,
        David Heidelberg <david@...t.cz>, linux-media@...r.kernel.org,
        linux-arm-msm@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org, Johan Hovold <johan+linaro@...nel.org>,
        Bryan O'Donoghue <bryan.odonoghue@...aro.org>
Subject: Re: [PATCH v3 4/7] arm64: dts: qcom: sc8280xp: Add Venus

On Mon, Jan 26, 2026 at 11:00:25AM +0100, Konrad Dybcio wrote:
> On 1/25/26 4:33 PM, Dmitry Baryshkov wrote:
> > From: Konrad Dybcio <konradybcio@...nel.org>
> > 
> > Add the required nodes to enable Venus on sc8280xp.
> > 
> > [ bod: added interconnect tags ]
> > 
> > Signed-off-by: Konrad Dybcio <konrad.dybcio@...aro.org>
> > [ johan: use sm8350 videocc defines ]
> > Signed-off-by: Johan Hovold <johan+linaro@...nel.org>
> > [ bod: dropped video encoder/decoder declarations ]
> > Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@...aro.org>
> > [ db: dropped llcc icc, switched to sc8280xp compat, added more freqs ]
> > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@....qualcomm.com>
> > ---
> 
> [...]
> 
> > +			venus_opp_table: opp-table {
> > +				compatible = "operating-points-v2";
> > +
> > +				opp-720000000 {
> > +					opp-hz = /bits/ 64 <720000000>;
> 
> You need to div3 all of these, otherwise this LOW_SVS OPP
> will actually apply a more-than-TURBO_L1-requiring frequency..

Hmm, is the OPP table for SM8250 then also incorrect?

I cross-checked SM8250 and Kodiak against, msm-4.19 and msm-5.4
correspondignly, the OPP tables are written in the same way.

> 
> [...]
> > +		videocc: clock-controller@...0000 {
> > +			compatible = "qcom,sc8280xp-videocc";
> > +			reg = <0 0x0abf0000 0 0x10000>;
> > +			clocks = <&rpmhcc RPMH_CXO_CLK>,
> > +				 <&rpmhcc RPMH_CXO_CLK_A>,
> > +				 <&sleep_clk>;
> > +			power-domains = <&rpmhpd SC8280XP_MMCX>;
> > +			required-opps = <&rpmhpd_opp_low_svs>;
> 
> AFAICS the PLLs will not turn on if *MX* is at < LOWSVS, but they still
> need to be scaled 1:1 with MMCX as the freuqency rises, so you need to
> wire up 2 power domains to the OPP table

I don't see this being done for SM8250, should it also be fixed? On
SM8550 we indeed manage MMCX and MX together. Should SC7280 also scale
both CX and MX together?

> 
> PLL0 supplies core0 (iris) and PLL1 supplies core1 (CVP)

--