From patchwork Thu Feb 10 10:06:36 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Hewitt X-Patchwork-Id: 12741641 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 B8942C433EF for ; Thu, 10 Feb 2022 10:08:02 +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:MIME-Version:List-Subscribe:List-Help: List-Post:List-Archive:List-Unsubscribe:List-Id: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:In-Reply-To:References: List-Owner; bh=LSYKYxLEzweODyp3rPs/iwNcOKqWf5hiPL0fGDezNgE=; b=YeIUDCLtgrK6J0 WV5SMYOx2h7TFL4rKc5REhbFLwElKYBoVWe2SH2JvvNDTebSFQvMuylPbWN4TeAwjZ28R3RLi/m7d YlMzPlImSziloIADXU+Kl1jVMG9LeLJI2zT8K5rtNW9SwUl+uFQLT1la1moGYxwWGnAudIMF+liTe najgGvHxC3wjnmiuUJ2crZhJXOO+0mHCH/cSJOvipEustXB7SpjvribVAB/B3hThReKZ40wheJipR su17TgkzW1f3N6TcHYl36HMeVi6PzR8c0q1lAKhYDZBvH3P5B4IKh3eKmHGL8TwDEnH8L7aEKNE8g ZtKDWbuHVg96rgetDbvA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nI6Lg-003OoM-6o; Thu, 10 Feb 2022 10:06:48 +0000 Received: from mail-wr1-x433.google.com ([2a00:1450:4864:20::433]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nI6Lc-003On9-DC; Thu, 10 Feb 2022 10:06:46 +0000 Received: by mail-wr1-x433.google.com with SMTP id e3so8666862wra.0; Thu, 10 Feb 2022 02:06:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id; bh=FPD4xO1P+78Y/NZipV2Yc+8FswUAtN3q8mItY6ywkSw=; b=QmQF9NFofioCPqaRQ/xtXqTWiKFv4fISuIYU/wppTpOUOYT2oVFrmKM30hyzW9XOXF weBSfLkDIzwC1gq4FYIaxqJgEPcSPslh2ZFFj0QKwr1dZpdkTG4mY26D2d5f11oX5Z8g rdh4qDGsYSsM1lpbHauTAINYBvOoRf9FIJaLrvgFIPLuqVJ2so1FhC+DKdkTa+naJUvg /VVYAeZUAQ89iROPos+uEAXr4t5L3DVAJfZKHVgqtfHnwYAqBayZAnIDILP3VHZwfoRw yNdFl0/SYw3wg5pVhC7EA/ND4xvWLyL2c2zMbD7GLBUCK4Ov6p4pmxrvUsoBRwFtYNxS A3bQ== 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:date:message-id; bh=FPD4xO1P+78Y/NZipV2Yc+8FswUAtN3q8mItY6ywkSw=; b=OSGfpFCBThRMRxrw5kkq37fzmQ2yFugb6DYKdw7fBQ2i8YOl8Ry4kz/T98Z57vd6HJ h6QLOvvlADDLB7dNgfpDfOkeXLeenDdT0P/TKPsa0LXK4WRKCflJNUSamKxRrj9tZCHa akqA+8OyXBfXCwRyn0EC6+wRpqLWJY0j4Lsb/nfl5ZKD/1ajdDKcYVLNN8Xoc1FNSA3H EXLAlK8PLl5bek0/v8xyNt7wx8qvlxE1U/1Y8ds63TcRPHumK/0+931cJZx8bBQrqm9+ hDmwPTMp5q9W2OKLrrGAerkRyKQ/FLiyJ2CFuStWCPHA+MMJacOOWTd9Y4mCxhaOPjGI k/VA== X-Gm-Message-State: AOAM531HqbWT1TSKmpbua81p6d2/Q9kz0OJB3Rfu1rjcqVfOUP2t4g6n rvfQaKx+b/xStS8sJrgIVEM= X-Google-Smtp-Source: ABdhPJz28f2M3YAckbDT3m5BYofZoOYoV0Zalqy9f2eHSZ/BpSZ+pd3QtbiwxftomVxupxK/KE+sow== X-Received: by 2002:adf:f64e:: with SMTP id x14mr5491755wrp.698.1644487602942; Thu, 10 Feb 2022 02:06:42 -0800 (PST) Received: from localhost.localdomain ([87.200.95.144]) by smtp.gmail.com with ESMTPSA id g15sm18817494wri.82.2022.02.10.02.06.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 10 Feb 2022 02:06:42 -0800 (PST) From: Christian Hewitt To: Rob Herring , Mark Rutland , Kevin Hilman , 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: [PATCH v2 0/2] arm64: dts: meson: remove CPU opps below 1GHz for G12B/SM1 Date: Thu, 10 Feb 2022 10:06:36 +0000 Message-Id: <20220210100638.19130-1-christianshewitt@gmail.com> X-Mailer: git-send-email 2.17.1 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220210_020644_464654_429973BA X-CRM114-Status: GOOD ( 11.91 ) 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: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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. 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. [0] https://github.com/khadas/linux/commit/20e237a4fe9f0302370e24950cb1416e038eee03 Changes since v1: - Split into two patches to allow for separate Fixes tags - Minor edits to commit messages for brevity and typos Christian Hewitt (2): arm64: dts: meson: remove CPU opps below 1GHz for G12B boards arm64: dts: meson: remove CPU opps below 1GHz for SM1 .../boot/dts/amlogic/meson-g12b-a311d.dtsi | 40 ------------------- .../boot/dts/amlogic/meson-g12b-s922x.dtsi | 40 ------------------- arch/arm64/boot/dts/amlogic/meson-sm1.dtsi | 20 ---------- 3 files changed, 100 deletions(-)