From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id DEBC4D44D43 for ; Wed, 6 Nov 2024 10:29:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type: Content-Transfer-Encoding:MIME-Version:References:In-Reply-To:Message-ID:Date :Subject:Cc:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=R33AHOEKuWVl8dftmRKyPE5U6BtAYCDsZvIA1WDMh7s=; b=GUsPnFbpAkbXvJ8EXxWhsm1pBf BOqcsshQLOnNzPztczCyeJ9w2UNX80dRYehC4qcFoEbtAnnZqUMjbWFBlV3AzYZ5MXfLM6WnH1cfW jMdHYdHsrWytZmCFkWSOIyImjHRL/c8yM5jtj3eQBcdtcGg8eZgpku0S8CUnLbCVHcstGijVIm6QZ thZpYSdm/qpPSgDqlWw/aVsCbrKPP28lp39Ax3Exo+7OBbYj/lBMsofsW+YS9+HrK0dj1qYLkB9RQ SI4iaLCmlgqf7DZyJaL/GKQqioBGW8COaMkd/+m9SJD3McWmEpO//7LVID0Gw94ZdqvTO1XnVhW7Q tB2CDOlQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1t8dHX-00000002kNf-1hIu; Wed, 06 Nov 2024 10:28:59 +0000 Received: from gloria.sntech.de ([185.11.138.130]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1t8cXl-00000002aff-0TsF; Wed, 06 Nov 2024 09:41:42 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sntech.de; s=gloria202408; h=Content-Type:Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=R33AHOEKuWVl8dftmRKyPE5U6BtAYCDsZvIA1WDMh7s=; b=P8IrTqVCjorN7eadZJASD5gDV+ DkgY0GG4hZ4lNvGNzMranIQVOzUUk17FfkTOySdqpwtT0VB/ElK2uHdIseXsi7JazCi9gvjRaMGUH ZvbopYu7W+ndp1Mdx1LHimV2R//HGArXbV45ZVybT9wm5NBZWFz4NZQkOP5nD0pW0Kw//PRtmeOhq 8JrBEUhzc3tV/pPX4da5cKaI04Ne5SKcOEiTkROu9S+HIs0U5a8Smmd6/Bb8zyaL5Pix4j/lqcAsw haN4uGgxT/K8U1tTeTur/kQx0hkI3+wr/0K5UULXuJzRY0uvUTtgHFDJpLNy+LBs2ZSJ6htduGd8B cvIMtT1A==; Received: from i53875b28.versanet.de ([83.135.91.40] helo=diego.localnet) by gloria.sntech.de with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1t8cXh-00062B-Pe; Wed, 06 Nov 2024 10:41:37 +0100 From: Heiko =?ISO-8859-1?Q?St=FCbner?= To: Dragan Simic , linux-rockchip@lists.infradead.org, Quentin Schulz Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, alchark@gmail.com Subject: Re: [PATCH v2] arm64: dts: rockchip: Add OPP voltage ranges to RK3399 OP1 SoC dtsi Date: Wed, 06 Nov 2024 10:41:36 +0100 Message-ID: <3252308.5fSG56mABF@diego> In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241106_014141_210986_306C22A7 X-CRM114-Status: GOOD ( 24.00 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Am Mittwoch, 6. November 2024, 10:32:06 CET schrieb Quentin Schulz: > Hi Dragan, > > On 11/6/24 9:33 AM, Dragan Simic wrote: > > Add support for voltage ranges to the CPU, GPU and DMC OPPs defined in the > > SoC dtsi for Rockchip OP1, as a variant of the Rockchip RK3399. This may be > > useful if there are any OP1-based boards whose associated voltage regulators > > are unable to deliver the exact voltages; otherwise, it causes no functional > > changes to the resulting OPP voltages at runtime. > > > > These changes cannot cause stability issues or any kind of damage, because > > it's perfectly safe to use the highest voltage from an OPP group for each OPP > > in the same group. The only possible negative effect of using higher voltages > > is wasted energy in form of some additionally generated heat. > > > > Reported-by: Quentin Schulz > > Well, I merely highlighted that the voltage was different on OP1 > compared to RK3399 for the 600MHz OPP :) > > So... If there's ONE SoC I'm pretty sure is working as expected it's the > OP1 fitted on the Gru Chromebooks with the ChromiumOS kernel fork > (though yes, I believe all Gru CB are EoL since August 2023). In the 6.1 > kernel fork, there's also no range: > https://chromium.googlesource.com/chromiumos/third_party/kernel/+/refs/heads/chromeos-6.1/arch/arm64/boot/dts/rockchip/rk3399-op1-opp.dtsi yeah, this somehow goes quite a bit into the "stuff that doesn't need to change" area. On the one hand it does make "some" sense to unify things if we're using ranges everywhere else. On the other hand, as Quentin noted below, all existing OP1 devices seem to run just fine, and there won't be any more entering the kernel. So what do we realisitically gain here, except hiding existing git-history under another layer? > So not sure we need to handle theoretical cases here. Will let > maintainers decide on that one. FWIW, there are two other OP1 devices, > the RockPi4A+ and RockPi4B+ which do not change the OPP either. Heiko