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 23CB638422E for ; Thu, 20 Aug 2026 05:40:01 +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=1787204402; cv=none; b=aLvwA9S7XBtiUpjVXz9GZxNAb6OS+PF7b1Xd/fGDSQ8D3bOxp1F/PQkAotua4kqMFxi/tKY4sXH5ysmi8bSk35SDF2EF4VjEYciWlO2ilebn+6wfqsAmwYeDJ/hhVBZ4NpmY2HbU06McmJ9/MTiOkldFohQUUQfVGpi7WUmgTTA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787204402; c=relaxed/simple; bh=sp37ocaCCvh8mEqRApDXVrf0uLcNlKjOJsf8ZDK0AHo=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=UO0Vf636HMbq5l7aZcOeDJdauwilBt4nSI93dliviZ+DR6QC/uY91Z4eESELsh34e22G07/eECzWDw200RYZiCxYA7jn0TQ4YqenOeayMaF0HRFGM1vTrz7YuciYPbqxyci4c6EpuaGJEmYhvqBI/3P/u14DgHvKMQXWr7wWXaQ= 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=his1vNIR; dkim=pass (2048-bit key) header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.b=aiI1QpJ5; 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="his1vNIR"; dkim=pass (2048-bit key) header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.b="aiI1QpJ5" Received: from pps.filterd (m0279863.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 67JL7Wmw1438609 for ; Thu, 20 Aug 2026 05:40:00 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= yr0+nommJTYT2OfeS5drPEQCv0SxAJnJA6eqUOoAqvE=; b=his1vNIRL81fFQ5W WGjoaYBN9WHeotrO6UdjbO5nrnHYbJb11Zwf4TsdUPfOpnprQm5ExqZ9+Rxt9sOg lu/KbJW+2LBvWRjZb4tIMe131XrqJxHeGoSvfEt5clDDkiMutXpZUfsStxwKT9h5 Megs24ykqR/owF0H9OH332lZmU+TYBfSRW93ZhRzlLvs5n0tDq3OfAxuIFeTfWKL sAZsMzq7mSa7edPDKCZasvXZSjYM5Nw4OPDs0rmkHt+RIBbaWBk1uDEs0IqLBG3e TLCSjvr41ueHnTe7Edjnqpd2F7qJsjec8Gw+SG7VRzMqWDWNuQNU6A/9RYG5eKx6 4/rFYA== Received: from mail-pg1-f200.google.com (mail-pg1-f200.google.com [209.85.215.200]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 4g5daa3st1-1 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NOT) for ; Thu, 20 Aug 2026 05:39:59 +0000 (GMT) Received: by mail-pg1-f200.google.com with SMTP id 41be03b00d2f7-cb11535e6a1so1526761a12.0 for ; Wed, 19 Aug 2026 22:39:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oss.qualcomm.com; s=google; t=1787204399; x=1787809199; darn=vger.kernel.org; h=content-transfer-encoding:content-type:in-reply-to:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:from:to:cc:subject:date:message-id:reply-to :content-type; bh=yr0+nommJTYT2OfeS5drPEQCv0SxAJnJA6eqUOoAqvE=; b=aiI1QpJ5uNPE6NJvMJOypeQYj4lbZ2IXpGS7GdHgkDFXNQqVnPPjlU/eIGfYfC064X A//ZNMIu0xbjcGKDD3cIbUZFaDrEy0W+BVvxqG7vx5E5PIOItmTTA0eLEOsD+R+6MJWt VVJe3ci0TA6DQnX1e6ijhME1TZsH/xk41IAPWbFBUfD9QCs0vmqzVTi46BriTReDTb0J IwAffCdUlYsdze1Ia+FGq9p2NMqIt8q+INbnECjnuqo0z22moo2yZD+NoMrlrr6QIQFF TkTHdNph/XS9lbZ231DisVK59mstItlBqZlL14NTy4cr7qpCMlAfhxUxdVT6rPgLPqEg 0hIw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1787204399; x=1787809199; h=content-transfer-encoding:content-type:in-reply-to:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=yr0+nommJTYT2OfeS5drPEQCv0SxAJnJA6eqUOoAqvE=; b=Yo5gyKnhwnPE7QdROoa/5+zMtLA6NQABGL+7khPwCvMSryuDpsZmvK8WJg8MxeGsha /hHvcSwdeLnBeqbOfbR4l/3R2jiubjz6vPHBYgf1lT2o0HJhTvo7b2zg6n7ZfLsag9T0 srdocwteV+5fDcjOf6lrLMU97RuMnq4W65nustK3FiXpwc39/W0BpydM0klCW16Z/vNP se4xfSG8wxKCA0VKtrKEvTW8RmJx6XFhIbHCFXIXusJEI4W+rIZOLvtR49hZllMRPrcT gipwj2EczEsfS0JGkyfKg0ItSXcjgXQ9THQl2XCgH7YdpziXXwqNllByTcaQTEJggGzJ kL4Q== X-Forwarded-Encrypted: i=1; AHgh+Ro6LTan2BChKsbLRNmYjaMwmsnV2LOyMyRSuUbKxaLBkmIEXIqG3IC6wejugCFOXp0EQ8KkCnVppC4=@vger.kernel.org X-Gm-Message-State: AOJu0YxqZ5NX+vEvD82xkNOwN0ZDkA9/rL/AFnoYVJRWmeQFpO1F7dvZ iGT6jPbUyxKlSSQ96aX8SzkRFTpvDkegLZRjnqOvO7oGn8M+dmxLwnFY7HxvfPLyJ2AK20YLTPy wN5PrgTNkUN7oaDdPhk3wnnQ1gC5DK4tKLG5EkBLOJYD13PyoI5abknkAh9GX7S+jvLYSYSA= X-Gm-Gg: AR+sD130ye1IPOmrokwXFX+LlE+tNWm3VPWgFeFWj6ezXchNVokRrNsrnVFtQFmO+ch Yr1jRC1BSy4V2a/j3I3YS8BD6yOTWUGRiApxnRwZT6gbUwz4hoTehVdJZDFK9EtxQ0nezH9LZM+ O4VSYysnNnZBGDTH/espRAvUyxVON2TA6ohelVZrWwxd7KDsBkxSsVIaP6iEfBYSm5LCfMlt4Qj 77FVisOhMiPWPMCGzvkZ6MyDqhw3nCd7xV/RZhOsFZRO3XGX+rLZR2z94qJ+WvoNYlszjx4zpl/ O3pRsoSvqi26V6RkUxXAne/25bz2wzCT8Y49xYbfJOTs8RZOzHfantsK/1DOFYRp1Zl/YxoJ9ZY aJMhe+YRN9xHPjHWL6pY2aPgasDOJFjRJ9ih58pbCzLoZ0grsNSqMm5rU+uoH3tfb X-Received: by 2002:a05:6a21:3a85:b0:3cc:a18c:b6d1 with SMTP id adf61e73a8af0-3cd019dc603mr20385928637.17.1787204399314; Wed, 19 Aug 2026 22:39:59 -0700 (PDT) X-Received: by 2002:a05:6a21:3a85:b0:3cc:a18c:b6d1 with SMTP id adf61e73a8af0-3cd019dc603mr20385857637.17.1787204398872; Wed, 19 Aug 2026 22:39:58 -0700 (PDT) Received: from [10.133.33.27] (tpe-colo-wan-fw-bordernet.qualcomm.com. [103.229.16.4]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-cc15523b579sm1412666a12.3.2026.08.19.22.39.55 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 19 Aug 2026 22:39:58 -0700 (PDT) Message-ID: <181944c2-2484-4384-9c91-45cc87f31955@oss.qualcomm.com> Date: Thu, 20 Aug 2026 13:39:52 +0800 Precedence: bulk X-Mailing-List: linux-clk@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] clk: qcom: ipq-cmn-pll: keep the CMN block bus clocks enabled To: Konrad Dybcio , Stanislaw Pal Cc: Bjorn Andersson , Stephen Boyd , Michael Turquette , Mieczyslaw Nalewaj , Brian Masney , linux-arm-msm@vger.kernel.org, linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org References: <20260730191353.557494-1-kuncy7@gmail.com> <20260803091003.15285-1-kuncy7@gmail.com> <8af46926-fecc-4396-973e-2290ae285998@oss.qualcomm.com> Content-Language: en-US From: Jie Luo In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Authority-Analysis: v=2.4 cv=fv3sol4f c=1 sm=1 tr=0 ts=6a86932f cx=c_pps a=oF/VQ+ItUULfLr/lQ2/icg==:117 a=nuhDOHQX5FNHPW3J6Bj6AA==:17 a=IkcTkHD0fZMA:10 a=Sv0fKeRqtYgA:10 a=s4-Qcg_JpJYA:10 a=VkNPw1HP01LnGYTKEx00:22 a=u7WPNUs3qKkmUXheDGA7:22 a=yOCtJkima9RkubShWh1s:22 a=BrIDYzEHq6298WO724AA:9 a=3ZKOabzyN94A:10 a=QEXdDO2ut3YA:10 a=3WC7DwWrALyhR5TkjVHa:22 X-Proofpoint-GUID: 9hGU9muFjP_qHkQihR1UAS6OuYc5bwqO X-Proofpoint-ORIG-GUID: 9hGU9muFjP_qHkQihR1UAS6OuYc5bwqO X-Proofpoint-Spam-Info: AW1haW4tMjYwODIwMDAzOSBTYWx0ZWRfX4zfj/UnWXxS0 X7/Utzdc7s+44tgsQ5yzP+OaWGAFv8j++aFmhs7m/yrNokGWSSIlEgdXRq9ccQJnSlhfYxBYLnp VgmEkF4oESrrtFV4dpOKY0T18erdIXk= X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwODIwMDAzOSBTYWx0ZWRfX3WJrqSZJHFAX rLuTHxxEHJlKVxLqC+J8wLuhaddzq6OjTNEKwPjDzPzyWs2ivo3FwLWjxz+puGPTTuEqBRbcEvt U1ss8v2foAtg94nH6ifIhshZ6n5nWANZnaJ2gTs8GVHpL6NVGNSxIhfywCULosYGuhguPF5sKcK c4AvsH9Z1nVHw5ULdrbVQARn+LxtsV8SuQ5AON3FN7DxIGrxXaBpLojBqNiZqEsxu2nTu6BpDBo /s9ER96tpZoZfRpWGnWbUieNr9AQcLnqZwrQzSsOzqdhCPShYZn9MHkqhJ6QsFbhT0tTR+sViVS AGS7x8D7rQbBYGPJtEZZGHxVfeLdrxPQGGxp6FH0bgSHgXV89PCMHVUChp+A8GRLAk5/G/JMgj2 29zhJyLz0YiL0ajVZnqeguqEvsdQQLYJufZKU/uldDCA863RJ2Pmmb8m+vtEHjvLCS0h0AzxGAb 85xILadD18zWPOYxpvg== X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1176,Hydra:6.1.134,FMLib:17.12.100.49 definitions=2026-08-19_06,2026-08-19_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 phishscore=0 bulkscore=0 spamscore=0 adultscore=0 suspectscore=0 impostorscore=0 lowpriorityscore=0 malwarescore=0 priorityscore=1501 clxscore=1015 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606150000 definitions=main-2608200039 On 8/19/2026 9:00 PM, Konrad Dybcio wrote: > On 8/4/26 1:03 PM, Jie Luo wrote: >> >> >> On 8/3/2026 5:10 PM, Stanislaw Pal wrote: >>>> The CMN PLL AHB/SYS clocks will remain enabled as long as a downstream >>>> consumer of the CMN PLL clocks is active — this behaviour was confirmed >>>> experimentally on the IPQ9574 platform as example. >>> That is exactly the mechanism - and it is exactly what IPQ5018 does not >>> have. On IPQ9574 the nsscc node consumes the CMN PLL outputs in DT: >>> >>> ipq9574.dtsi: >>> nsscc: clock-controller@39b00000 { >>> clocks = <&xo_board_clk>, >>> <&cmn_pll NSS_1200MHZ_CLK>, >>> <&cmn_pll PPE_353MHZ_CLK>, ... >>> >>> so the device link holds the supplier active, which is what your >>> insmod/devmem experiment shows. >>> >>> On IPQ5018 there is no such consumer: nothing in ipq5018.dtsi references >>> any cmn_pll output clock - the only occurrences of the phandle are the >>> provider node itself and its own assigned-clocks. The actual users of >>> the CMN outputs on this SoC (the internal GE PHY and the uniphy blocks) >>> take them directly in hardware, with no DT linkage, so no device link >>> ever holds the provider active. A few ms after probe the autosuspend >>> gates the AHB/SYS clocks, and the box dies on the next bus access - >>> which is the measured behaviour the patch description quotes. >> >> The CMN PLL output clocks do not depend on the AHB or SYS clocks. They >> continue to operate correctly at the fixed rates even when the AHB >> and SYS clocks are disabled. Therefore, once the CMN PLL module is >> loaded, its output clocks are expected to operate at the correct >> frequencies. > > Linux sees there's no consumers for the clocks the CMN PLL provides > and gates them, subsequently also gating the PLL itself as all of > its children become offline. > > I can't find the docs that would show me what IPs consume this block, > could you please help out here Jie? > On IPQ5018, the CMN PLL provides a 50 MHz output clock that is used as the reference clock for the connected Ethernet device. > Konrad