From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 34845443E4C; Wed, 29 Jul 2026 09:54:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785318873; cv=none; b=Tx0pCpLUhVD1pVBbcjA4FI3LBKZqqeow03V3PaXXV6hN1jd90/Srgjhan7jAguANCFY3R/jVl2rXejHVhLxpCCtmWL/15NFD3u9kDGR5vRvlrMec3NFUK2J4HbQSu3Tfo9fa4y2uYOtqHVK2wAFT7mFK8POE+tlctTpi/I/xDSs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785318873; c=relaxed/simple; bh=imui3R/0vYCF6N922AQBFiU71XBR6Z/ucfaxKG1HgWI=; h=Date:From:To:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=JHh2oolQR3XzZ2hUad8uLzgeOfxPbPYqAlftQH0m56Di4pV1oNNXpgzDGCAx76RsvcunpYE9Lfkzlo+ePjk9Vz3EuTtwp3zs9BoKCiyRgZVu/Lz27G+W65eoLRBkSIIBcyFvYRChrmGZGg/9xvzuL3uB/K0rCg4LenyR0Y79jA4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=F8PmnrTG; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="F8PmnrTG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6094A1F00A3A; Wed, 29 Jul 2026 09:54:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785318871; bh=LVcDA3xezlmTl1NajKjqRETDsHsLNfimeEju9cIQEX0=; h=Date:From:To:Subject:References:In-Reply-To; b=F8PmnrTG9vWE4KhJExVOol4GWqwd64EU0COppIy71qbYl7g1r7SiwmvxCs0OMAAPT XvFiCJaB7m3vqW7xWDOyC3mGNemvbhFLA7T/i6cWeM9OFMVaDDu9VOYdvAKe3GyDEP X7QtKnQLBFlOW0BarvJv96ZtJ2D7LD58Nt95nLJCmXBJav6Sv4+CnU6/9GmBXNeIyB dzUp6n/oLycEU6As/yErwkBlN/YVgcamBKxIIZKpXEDpk5lXf5r2YFwY0oiZmRMxME 3634fzXXAp2gSVaM6OZmw0KCxqg6MzLIlCdelHEg3T1DMw0Cx8Eyj5P5UVZ8v19MmR 6QG7ctLhUm3gg== Date: Wed, 29 Jul 2026 09:54:29 +0000 From: Yixun Lan To: sashiko-reviews@lists.linux.dev, linux-kernel@vger.kernel.org, Rob Herring , Krzysztof Kozlowski , Conor Dooley , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Shuwei Wu , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , "open list:RISC-V SPACEMIT SoC Support" , "open list:RISC-V SPACEMIT SoC Support" Subject: Re: [PATCH 1/3] riscv: dts: spacemit: Add cpu scaling for Milk-V Jupiter Message-ID: <20260729095429-GKH76518@kernel.org> References: <20260728211020.1248676-1-aurelien@aurel32.net> <20260728211020.1248676-2-aurelien@aurel32.net> <20260728211959.4174F1F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: spacemit@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Hi Aurelien, On 11:36 Wed 29 Jul , Aurelien Jarno wrote: > Hi, > > On 2026-07-28 21:19, sashiko-bot@kernel.org wrote: > > Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider: > > > > Pre-existing issues: > > - [High] This problem wasn't introduced by this patch, but wiring it up to cpufreq makes it a serious hardware safety risk: the CPU supply regulator (`buck1_0v9`) has an overly permissive maximum voltage constraint of 3.45V, which could physically damage the CPU. > > -- > > > > --- Patch [1]: [PATCH 1/3] riscv: dts: spacemit: Add cpu scaling for Milk-V Jupiter --- > > commit 4e25fb96470d1ad37415e03a27de699ef1f0da26 > > Author: Aurelien Jarno > > > > riscv: dts: spacemit: Add cpu scaling for Milk-V Jupiter > > > > This commit enables CPU DVFS on the Milk-V Jupiter board by including the OPP > > tables and wiring the CPU nodes to the CPU regulator supply. > > > > > diff --git a/arch/riscv/boot/dts/spacemit/k1-milkv-jupiter.dts b/arch/riscv/boot/dts/spacemit/k1-milkv-jupiter.dts > > > index b61f5995ec771..3c16d0c20050e 100644 > > > --- a/arch/riscv/boot/dts/spacemit/k1-milkv-jupiter.dts > > > +++ b/arch/riscv/boot/dts/spacemit/k1-milkv-jupiter.dts > > [ ... ] > > > @@ -107,6 +108,38 @@ &combo_phy { > > > status = "okay"; > > > }; > > > > > > +&cpu_0 { > > > + cpu-supply = <&buck1_0v9>; > > > +}; > > [ ... ] > > > @@ -209,7 +242,7 @@ pmic@41 { > > > dldoin2-supply = <&buck5>; > > > > > > regulators { > > > - buck1 { > > > + buck1_0v9: buck1 { > > > regulator-min-microvolt = <500000>; > > > regulator-max-microvolt = <3450000>; > > > > [Severity: High] > > This is a pre-existing issue, but by wiring up the CPU supply for cpufreq in > > this patch, does it introduce a severe hardware safety risk? > > > > The buck1_0v9 regulator retains a very permissive maximum voltage constraint > > of 3.45V. Because the safe physical limit for the CPU is 1.05V (as defined in > > k1-opp.dtsi), could this permanently damage the hardware if a kernel bug, opp > > misconfiguration, or privileged userspace requests a higher voltage up to the > > board-defined maximum? > > > > Should the board-level constraint be clamped to the safe physical limits of > > the CPU (e.g., 1050000 microvolts) to prevent the regulator from supplying a > > destructive voltage? > > This looks like a valid point. Yixun, I believe the commit a5d7000e1a17 > ("riscv: dts: spacemit: Add cpu scaling for K1 SoC") should be drop from > your tree until this is fixed, or at least it should not be pushed to > v7.3 if the regulator issue is not fixed. > Instead of dropping this patch, I'd like to get it fixed in tree, I don't want to hold on this patch, it's generally tested > I'll try to submit a patchset fixing that. > Yes, please, I think we still have time to get it in for v7.3 -- Yixun Lan (dlan)