From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx4.sberdevices.ru (mx4.sberdevices.ru [152.89.196.46]) (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 43BA52E973A; Fri, 23 Jan 2026 20:41:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=152.89.196.46 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769200893; cv=none; b=utK9dt12s8DknVXYijQurju7uBjooOxABVCAGQV7AX/uI/02nZahW0C1iexWbPoFuSTduR2RUOi084r7QBsbNmq0L0ffnuVuZsFyqeO6t+TV9K587nmNs2jZ1HyPLS/Ml52Zma4XxdxrOsblPaNYwxCO3AeINN6vs8B3kqymYDM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769200893; c=relaxed/simple; bh=oRazaIa6tt+1lSFNk7i2lmEsaGJy+Th/iSXWDVzH14o=; h=Message-ID:Date:MIME-Version:Subject:CC:References:From:To: In-Reply-To:Content-Type; b=FGopN7tULHQ9bP/hhk+zbM4KCtNj42zdNVcAnZquwo5tHKz4+AP/9C7jjXm1ya2hMbUETdDlHITU4mmG61BZJm46BgUQ58q6DM6HhxSanAI9oo/+lqYxVl5i3HFY9IjvsuLzI1JLLAWNGN6yRDAEHDw5wuCvC68xrLXSYxHhMdk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=salutedevices.com; spf=pass smtp.mailfrom=salutedevices.com; dkim=pass (2048-bit key) header.d=salutedevices.com header.i=@salutedevices.com header.b=JSGOdPxc; arc=none smtp.client-ip=152.89.196.46 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=salutedevices.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=salutedevices.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=salutedevices.com header.i=@salutedevices.com header.b="JSGOdPxc" Received: from p-antispam-ksmg-sc-msk02.sberdevices.ru (localhost [127.0.0.1]) by mx4.sberdevices.ru (Postfix) with ESMTP id 8BF0040020; Fri, 23 Jan 2026 23:41:20 +0300 (MSK) DKIM-Filter: OpenDKIM Filter v2.11.0 mx4.sberdevices.ru 8BF0040020 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=salutedevices.com; s=post; t=1769200880; bh=9k7W830smXgr5e8HHqIJIuTQyT0nFUdeI8UbwjsPS/A=; h=Message-ID:Date:MIME-Version:Subject:From:To:Content-Type:From; b=JSGOdPxcLB1ayij5p97TTAAfzq2uM86eVpbHR7DYcuuwyBHRsylYMjeQoPm9+LRWw PHUVbhi1WGkyrThOgwqV6vy2ciLMAOM48nZBfxjIVLa5D0gYK+IUBbKE68xyPnzPY7 yQ11mF+l8T/S034UMSExmD1kHJdeIgQLW+i0D4At8s3qFKHZ/vre4kUCyWIJe5d5ws F7TfnyXpANyIHsHDaZs3VXSgy0PiMekkM2ziD8Vyw8FI1iPUQWwos38QEIa/UG9H0w NfaiJQbg/c5uapNJ81PuQXpHKu2zw0Q0V7pnPY8QfEc/1rGKa6AFFpJVfLjzUPvcN1 +Cmb7rdnNJCdg== Received: from smtp.sberdevices.ru (p-exch-cas-s-m1.sberdevices.ru [172.16.210.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "sberdevices.ru", Issuer "R12" (verified OK)) by mx4.sberdevices.ru (Postfix) with ESMTPS; Fri, 23 Jan 2026 23:41:19 +0300 (MSK) Message-ID: <09df45e1-90b5-4618-9197-c724142bd83a@salutedevices.com> Date: Fri, 23 Jan 2026 23:40:32 +0300 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [DMARC error] [PATCH v3 3/3] arm64: dts: meson-s4-s905y4-khadas-vim1s: add initial device tree CC: , , , , , , , , "kernel@salutedevices.com" , , , , , References: <20260115030015.1334517-1-nick@khadas.com> <20260115030015.1334517-4-nick@khadas.com> Content-Language: en-US From: George Stark To: Nick Xie In-Reply-To: <20260115030015.1334517-4-nick@khadas.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: p-exch-cas-a-m1.sberdevices.ru (172.24.201.216) To p-exch-cas-s-m1.sberdevices.ru (172.16.210.2) X-KSMG-AntiPhishing: NotDetected, bases: 2026/01/23 18:51:00 X-KSMG-AntiSpam-Auth: dkim=none X-KSMG-AntiSpam-Envelope-From: gnstark@salutedevices.com X-KSMG-AntiSpam-Info: LuaCore: 86 0.3.86 47cb2a3d3f5c7e795bff2d0998e8c196722872ab, {Tracking_uf_ne_domains}, {Tracking_bl_eng_cat}, {Tracking_from_domain_doesnt_match_to}, smtp.sberdevices.ru:5.0.1,7.1.1;elixir.bootlin.com:7.1.1;127.0.0.199:7.1.2;d41d8cd98f00b204e9800998ecf8427e.com:7.1.1;lkml.iu.edu:7.1.1;salutedevices.com:7.1.1, FromAlignment: s X-KSMG-AntiSpam-Interceptor-Info: scan successful X-KSMG-AntiSpam-Lua-Profiles: 199802 [Jan 23 2026] X-KSMG-AntiSpam-Method: none X-KSMG-AntiSpam-Rate: 0 X-KSMG-AntiSpam-Status: not_detected X-KSMG-AntiSpam-Version: 6.1.1.20 X-KSMG-AntiVirus: Kaspersky Secure Mail Gateway, version 2.1.1.8310, bases: 2026/01/23 17:16:00 #28145625 X-KSMG-AntiVirus-Status: NotDetected, skipped X-KSMG-KATA-Status: Not Scanned X-KSMG-LinksScanning: NotDetected, bases: 2026/01/23 18:51:00 X-KSMG-Message-Action: skipped X-KSMG-Rule-ID: 5 Hello Nick On 1/15/26 06:00, Nick Xie wrote: > The Khadas VIM1S uses the Amlogic S905Y4 SoC, based on the > Amlogic S4 SoC family, on a board with the same form factor as the > VIM/VIM2/VIM3/VIM4 models. Serial debug console, ethernet, SD card > work with this initial device tree. ... > + }; > + > + /* SY8120B1ABC DC/DC Regulator. */ > + vddcpu: regulator-vddcpu { > + compatible = "pwm-regulator"; > + > + regulator-name = "VDDCPU"; > + regulator-min-microvolt = <689000>; > + regulator-max-microvolt = <1049000>; > + > + vin-supply = <&main_5v>; > + > + pwms = <&pwm_ij 1 1500 0>; > + pwm-dutycycle-range = <100 0>; > + > + regulator-boot-on; > + regulator-always-on; > + /* Voltage Duty-Cycle */ > + voltage-table = <1049000 0>, > + <1039000 3>, > + <1029000 6>, > + <1019000 9>, > + <1009000 12>, > + <999000 14>, > + <989000 17>, > + <979000 20>, > + <969000 23>, > + <959000 26>, > + <949000 29>, > + <939000 31>, > + <929000 34>, > + <919000 37>, > + <909000 40>, > + <899000 43>, > + <889000 45>, > + <879000 48>, > + <869000 51>, > + <859000 54>, > + <849000 56>, > + <839000 59>, > + <829000 62>, > + <819000 65>, > + <809000 68>, > + <799000 70>, > + <789000 73>, > + <779000 76>, > + <769000 79>, > + <759000 81>, > + <749000 84>, > + <739000 87>, > + <729000 89>, > + <719000 92>, > + <709000 95>, > + <699000 98>, > + <689000 100>; > + }; > +}; Thanks for the patch. Since you have khadas mail I'm pretty sure you've had the possibility to test it on the real vim board and I just don't get it how it works with the voltage table above. The problem is that pwm is calculated incorrectly in the upstream pwm-meson driver. That voltage table appeared to be used in early amlogic bl loader and appropriate pwm is initialized from a table's record. Duty cycle value is translated to pwm regs correctly. Later when kernel start running pwm-regulator driver is probed. It reads the pwm regs, calculates back duty-cyle and search it in the table. Since calculation algos are not match and the table doesn't contain full range of 0-100% values regulator driver doesn't find current voltage. In such case regulator core sets the minimum voltage from the table [1] and the SoC may hang (depending on board) due to minimum voltage may be too low for the current frequency SoC uses. Or I'm missing something? There's not-yet-reviewed patch that fixes pwm algo [2]. There's calculation example in the cover letter. [1] https://elixir.bootlin.com/linux/v6.19-rc5/source/drivers/regulator/core.c#L1227 [2] https://lkml.iu.edu/2412.3/00826.html -- Best regards George