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 153A3C433EF for ; Wed, 9 Feb 2022 20:47:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:References :In-Reply-To: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=xHZITvkYp+slSiK3inMky5fcfU2DByJ/wVi+T4p5CtI=; b=KN1Oa7cy8KFaTY 4T19CFMVN+bVC4iknXDqTIm+QoG/yh2C/tDU1YbIHF9H6KYosRuxuQBTd9Ah+F0WQXH2BqOVExWGX w223xDnUZHGczmoy6+xj4z9umq1eB7pQkhjY7+aqUFv8nwZ8XN7HKVs94wQ3VGe/AUr34mfrj8nCV OA1Hz79wUUmMUXkYGegP8Hf3cXBseiSOy/hBAscN7DYoUxBrbh1xCOz8MEVOQNDTG4xxQxoAa6g3A qKzj3I5wydCevzXcQh0XzcXXVDDDrFA59j3jsB0oV3z8D2u0X+7dQhDi0Mp2PhkRcnC/+TrjOkhsW YOdtLIc5ocn2uYyhknXA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nHtr9-001cX5-DM; Wed, 09 Feb 2022 20:46:27 +0000 Received: from mail-pf1-x42a.google.com ([2607:f8b0:4864:20::42a]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nHtr5-001cVX-7r for linux-arm-kernel@lists.infradead.org; Wed, 09 Feb 2022 20:46:25 +0000 Received: by mail-pf1-x42a.google.com with SMTP id u16so780078pfg.3 for ; Wed, 09 Feb 2022 12:46:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baylibre-com.20210112.gappssmtp.com; s=20210112; h=from:to:cc:subject:in-reply-to:references:date:message-id :mime-version; bh=78nJXDfmr//iqkCpJCXmmDUOzZ8w2oIwGyGP9nLOEfc=; b=Vunja1WpaNu5p6wfFPAjyHKQ8YyGTJ6zeo0OoPoWTGhTqeSRtYhi4zvfqDseMj3UaW f84lAthwXw3UmvPfjk8ltUYN+JefaEAAuhJdgRwPHutOufpI+G0S6FKbZCIaBsXQfbq6 NOLHolki2PKzt93ROK4Fj786sndwLxv4UVwArcIECjJ8Gu6H4LxHwMAT0wq3Nvz2Qjvw PvdCas6sjRqGl9+A1kZY31Y9t8HYwweJ4LlzpklB2wR6mNTB0J1CCIzM5BRCQWAGOGml PwNraH9ZBkJfm6V1UR7bFUixi9NJ7gwmInSV888GLX2Gia9BNowSFWJZMz90TiGIqWSV CQhw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:in-reply-to:references:date :message-id:mime-version; bh=78nJXDfmr//iqkCpJCXmmDUOzZ8w2oIwGyGP9nLOEfc=; b=tus50ciw3QddXJq6kMONhbnS1gXQ2n7Wsf3ldV9Sp7rFhLP8L32Wg0wZKfB54ikwKB 41zNuiRnE6b8HlKDaSBbWrBSgvj2LmSSexQKg+y69/YHRQaQYwJMjYrIfZlBRAMyUERF DIX6xI35pUDde5ZVuKZp/8m1CISbI7LzM9z60pSsqaSPSnwY5ErzD4pHy6IeANzkb3LT 8f62071n8lL8mA9mNyfnoKUt/+qZCI0xm6z6rcutWgooxylC1HDp9kZ5WgIj7V4hz1kb 4tzYjDZtpwviEzbHTpCnACLFM6d2fvaCu3mlTJU4/T0xVnyRPltNsmGmLuUwgh9zq8/F r3Ww== X-Gm-Message-State: AOAM532UBvH5OHWxGqdXTep1KSyrBFvXZQ2AJibA9aA+pFdHTMVs5o9K 6688R+Mh6/UE9Q+3AZrKgnHrsQ== X-Google-Smtp-Source: ABdhPJy1EPPPscPrTxELXF/O0JLfaezpMxmi2sVgyHAvQdoKK3cPB+OENHfWbpQDEBnNlosgsUtiKQ== X-Received: by 2002:a63:3d85:: with SMTP id k127mr3361676pga.350.1644439582562; Wed, 09 Feb 2022 12:46:22 -0800 (PST) Received: from localhost (c-71-197-186-152.hsd1.wa.comcast.net. [71.197.186.152]) by smtp.gmail.com with ESMTPSA id k14sm8399557pgt.73.2022.02.09.12.46.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 09 Feb 2022 12:46:21 -0800 (PST) From: Kevin Hilman To: Christian Hewitt , Rob Herring , Mark Rutland , Neil Armstrong , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-amlogic@lists.infradead.org, linux-kernel@vger.kernel.org Cc: Christian Hewitt Subject: Re: [PATCH] arm64: dts: meson: remove CPU opps below 1GHz for G12B/SM1 In-Reply-To: <20220209135535.29547-1-christianshewitt@gmail.com> References: <20220209135535.29547-1-christianshewitt@gmail.com> Date: Wed, 09 Feb 2022 12:46:21 -0800 Message-ID: <7ha6ezojj6.fsf@baylibre.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220209_124623_366724_714B2E87 X-CRM114-Status: GOOD ( 17.65 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Christian Hewitt writes: > Amlogic G12B and SM1 devices experience CPU stalls and random board > wedges when the system idles and CPU cores clock down to lower opp > points. Recent vendor kernels include a change to remove 100-250MHz > (with no explanation) [0] but other downstream sources also remove > the 500/667MHz points (also with no explanation). Unless 100-667Mhz > opps are removed or the CPU governor forced to performance, stalls > are observed, so let's remove them an improve stability/uptime. > > [0] https://github.com/khadas/linux/commit/20e237a4fe9f0302370e24950cb1416e038eee03 hehe, not a very helpful changelog in that khadas kernel commit :( > Signed-off-by: Christian Hewitt > --- > Numerous people have experienced this issue and I have tested with > only the low opp-points removed and numerous voltage tweaks: but it > makes no difference. With the opp points present an Odroid N2 or > Khadas VIM3 reliably drop off my network after being left idling > overnight with UART showing a CPU stall splat. With the opp points > removed I see weeks of uninterupted uptime. It's beyond my skills > to research what the cause of the stalls might be, but if anyone > ever figures it out we can always restore things. NB: This issue > is not too widely reported in forums, but that's largely because > most of the Amlogic supporting distros have been including this > change picked from my kernel patchset for some time. Very interesting. I've also noticed instability across suspend resume on VIM3/VIM3L and only got as far in debugging to noticing it was DVFS/OPP related, but didn't get much further yet. I'll give this a try to see if it helps. Thanks for finding & posting! Kevin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel