From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0a-0031df01.pphosted.com (mx0a-0031df01.pphosted.com [205.220.168.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 869AC3234 for ; Tue, 31 Dec 2024 16:21:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.168.131 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735662075; cv=none; b=unNsD5M+qLLH71FSNXwZ5Gj4ETzHe7H3QNmwtD5PbmH52JJ/VJNNuXpz7nG2+N/0iQkmqHhxMeoOBC/97c0Vgu9Kq8iO8OEy7Y6wOfbdwkt5z/wIDDf5DFp1/e1WlYGIEmrvMyqoIw6saX/VGsvARob67BZSjl22QVSnHbVquTg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735662075; c=relaxed/simple; bh=2RF9iuBH0SUoO9XGLxM6Wzu/BqIdZFN/mDeBVPLgTwE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=f/QyIY7zdQEJ28ucw/rbzs7zH8CVFCle0vaNIZNiRpe6V60c5zm6IW04dgqplxt3OSFeAIrua6/jsGQKmROEr0pGYwYUsBO3HHP5wNd2a4HKHRy8t2VU7YfhCp1QRB+0skRddxy5qlGZAfjYPckXIyICEEwqdwToBnvwjxZhg4o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oss.qualcomm.com; spf=pass smtp.mailfrom=oss.qualcomm.com; dkim=pass (2048-bit key) header.d=qualcomm.com header.i=@qualcomm.com header.b=CNu6PG8c; arc=none smtp.client-ip=205.220.168.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oss.qualcomm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=oss.qualcomm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=qualcomm.com header.i=@qualcomm.com header.b="CNu6PG8c" Received: from pps.filterd (m0279867.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 4BVE3gvh014803 for ; Tue, 31 Dec 2024 16:21:13 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=qualcomm.com; h= cc:content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=qcppdkim1; bh= ljy3Qb4AXKfr9HphI58r4Qn4mu2yQF6pmaRFo1VDtqU=; b=CNu6PG8c5lfHt2dL dZLW+iX9jLVj8BQ5QfNT6JFhmcsrXee/qWF3AmM+XDe9xeTm5wSvrwk6qq5469VI VogGgD7HTn4NkRDPSJNjNpTBBQ1V80oXAYrxuv8adUlJiMAWTZTaRSHRcjfEr9iY agt+pdzqBRXW0PmKEIE7VqwG8oZWCPq+A6eU8IAJ6UtqiX6luv2yFZFOCzWf3Myr le/nCTLkXtdjoZ2asLIVhT81utk40cCn9rHYjAPTEYWfXNMtFRRO26KRGA4GoVtl tKaP19/BtbusfZMidHT4+/vp5M05/Eb6ExJoB8rnC0a98JMmnFWFbVkfshwDo/ag F0mx5A== Received: from mail-qk1-f200.google.com (mail-qk1-f200.google.com [209.85.222.200]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 43vj1ur6x7-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 31 Dec 2024 16:21:12 +0000 (GMT) Received: by mail-qk1-f200.google.com with SMTP id af79cd13be357-7b704c982eeso87590285a.1 for ; Tue, 31 Dec 2024 08:21:12 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1735662066; x=1736266866; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=ljy3Qb4AXKfr9HphI58r4Qn4mu2yQF6pmaRFo1VDtqU=; b=frKwpODNXedj1yVJCd0N0vTnkoZePUZTLkk/ty5BNKnZEjU8NJD19PpElXTpDW5ozm FaTVgMSUqbqXFbzjZEX0inAtq8HpUCCrWhIK/bwTnTwjCcbTaYUzFShd650gX+VjPpY4 puT7EHiR62mI+vhIe4DlhJzvmV1nOBL09/VwP6NzkXuDAmELOiqU8uCbDCbtKZIX7GAI wymHRFv2cDCN/F3WsVVxKHKYAIoEt+W8r+jJrnOQmIio+zaA5fiMU/TJZ9PZp1BhgC9X 1erJAsQBR2KNt+bTfyeBma5YCBXW0aM3kA7JzmGTpmL7Xay5SW7RsgFSt+XVL19sSbMs pNYQ== X-Gm-Message-State: AOJu0YymITn/SrewZAUc0x57+0Fv4cfYThISV7sMctnu5TDioRoD1hF2 JuauNabr7GVltVRqtQD7EO6VYD/psyRkc4X3drTlUYPv1CNcJMEvpM41um67k6yGEJc59OZg+q3 efYlT38aggIYmkScRVENQRhAWn4nx0ruKBoygVWzwuUxqEG3iBewR4f+1UvZ3uIIX X-Gm-Gg: ASbGnctqc+LjFaTpKNzOueUA/sWln543rzFsxBAcEgyx1nZDF4h0RFuK7QL4be8aIXb K7lpznmWlgRwPsWCg1XRhbfzbEfbeGx2pzXgjxsHNKET7W8kGVR/BLWQkJkmuALutaNxg0ar1a8 Hq52aN5jiN8xG1ilMJUEDESe+lInt2YG6PafVmmaH6CtUUKvO/+Ph41ZGiNZVeLx1Vu04PvnX/u yby+H5e7IgN67B+vKAZJe+WMKcGafeXFFtVzgdp91eF8b0udxUddTLbeTbEyshHkhfWNPubRGBO +BkamZl0rdZtXIQ3XyZud+H7s6pkjbjoVKU= X-Received: by 2002:a05:620a:2620:b0:7af:cac7:5017 with SMTP id af79cd13be357-7b9ba7322bbmr2404605285a.4.1735662064332; Tue, 31 Dec 2024 08:21:04 -0800 (PST) X-Google-Smtp-Source: AGHT+IH3W+kVRXZdSaW7DniEPJbMiXabPdArKM93olFDB2Kxk2mk1ehf3/y/E52cFnrn5gdU3D6fhA== X-Received: by 2002:a05:620a:2620:b0:7af:cac7:5017 with SMTP id af79cd13be357-7b9ba7322bbmr2404603585a.4.1735662063904; Tue, 31 Dec 2024 08:21:03 -0800 (PST) Received: from [192.168.65.90] (078088045245.garwolin.vectranet.pl. [78.88.45.245]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-aac0e894f2esm1614037866b.69.2024.12.31.08.21.02 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 31 Dec 2024 08:21:03 -0800 (PST) Message-ID: <1798bc04-4cda-45aa-b033-3cbafe7f8f54@oss.qualcomm.com> Date: Tue, 31 Dec 2024 17:21:01 +0100 Precedence: bulk X-Mailing-List: linux-arm-msm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 6/6] arm64: dts: qcom: Enable cpu cooling devices for QCS9075 platforms To: Manaf Meethalavalappu Pallikunhi , Konrad Dybcio , Wasim Nazir , Bjorn Andersson , Konrad Dybcio , Rob Herring , Krzysztof Kozlowski , Conor Dooley Cc: linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, kernel@quicinc.com References: <20241229152332.3068172-1-quic_wasimn@quicinc.com> <20241229152332.3068172-7-quic_wasimn@quicinc.com> Content-Language: en-US From: Konrad Dybcio In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Proofpoint-ORIG-GUID: oT2-hQXtNXoI6I9n813Trevp4WPvN-at X-Proofpoint-GUID: oT2-hQXtNXoI6I9n813Trevp4WPvN-at X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1039,Hydra:6.0.680,FMLib:17.12.60.29 definitions=2024-09-06_09,2024-09-06_01,2024-09-02_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 impostorscore=0 phishscore=0 adultscore=0 suspectscore=0 spamscore=0 lowpriorityscore=0 bulkscore=0 mlxscore=0 mlxlogscore=750 malwarescore=0 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2411120000 definitions=main-2412310138 On 31.12.2024 12:05 PM, Manaf Meethalavalappu Pallikunhi wrote: > > Hi Konrad, > > On 12/30/2024 9:05 PM, Konrad Dybcio wrote: >> On 29.12.2024 4:23 PM, Wasim Nazir wrote: >>> From: Manaf Meethalavalappu Pallikunhi >>> >>> In QCS9100 SoC, the safety subsystem monitors all thermal sensors and >>> does corrective action for each subsystem based on sensor violation >>> to comply safety standards. But as QCS9075 is non-safe SoC it >>> requires conventional thermal mitigation to control thermal for >>> different subsystems. >>> >>> The cpu frequency throttling for different cpu tsens is enabled in >>> hardware as first defense for cpu thermal control. But QCS9075 SoC >>> has higher ambient specification. During high ambient condition, even >>> lowest frequency with multi cores can slowly build heat over the time >>> and it can lead to thermal run-away situations. This patch restrict >>> cpu cores during this scenario helps further thermal control and >>> avoids thermal critical violation. >>> >>> Add cpu idle injection cooling bindings for cpu tsens thermal zones >>> as a mitigation for cpu subsystem prior to thermal shutdown. >>> >>> Add cpu frequency cooling devices that will be used by userspace >>> thermal governor to mitigate skin thermal management. >>> >>> Signed-off-by: Manaf Meethalavalappu Pallikunhi >>> --- >> Does this bring measurable benefits over just making the CPU a cooling >> device and pointing the thermal zones to it (and not the idle subnode)? >> >> Konrad > As noted in the commit, CPU frequency mitigation is handled by hardware as a first level mitigation. The software/scheduler will be updated via arch_update_hw_pressure API [1] for this mitigation. Adding the same CPU mitigation in thermal zones is redundant. We are adding idle injection with a 100% duty cycle as an additional mitigation step  at higher trip to further reduce CPU power consumption. This helps device thermal stability further, especially in high ambient conditions. I understood this much from the commit message. What I'm asking is, whether your solution actually works better than just letting Linux software-throttle the CPUs, preferably backed by some numbers. I'm also unsure how this is supposed to reduce power consumption. If the CPUs aren't busy, they should idle, and if they are not fully utilized, a lower frequency would likely be scheduled. Konrad > > [1]. https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/drivers/cpufreq/qcom-cpufreq-hw.c?h=next-20241220#n352 > > Best regards, > > Manaf >