From owner-freebsd-arm@freebsd.org Mon Feb 20 13:32:34 2017 Return-Path: Delivered-To: freebsd-arm@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 09BB5CE5689 for ; Mon, 20 Feb 2017 13:32:34 +0000 (UTC) (envelope-from jiashiun@gmail.com) Received: from mail-qt0-x234.google.com (mail-qt0-x234.google.com [IPv6:2607:f8b0:400d:c0d::234]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id CC43F1786 for ; Mon, 20 Feb 2017 13:32:33 +0000 (UTC) (envelope-from jiashiun@gmail.com) Received: by mail-qt0-x234.google.com with SMTP id x35so13036956qtc.2 for ; Mon, 20 Feb 2017 05:32:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to; bh=BkGaZcU/TyX8+mo+Rq1hVlhkGHsi14KW0iVegYS4WZg=; b=lZwsKKbbZnin165zyNZWrUK2dgp2Jrg0QHxgZTY3NFY8m10drOQKOA/f82Z6LvTPyd VXHpD9EFfDr3D3GFoTZnhkMyEboXa2xLosARq5Bx3giWutme00XGpPNdfqJ2sMD9fe6/ fNMnbQNsdrquJcJLOQpNMzZIwYUPFcxNb+WO/rZUV0DKfqm+fTeNq69nD8hdD4SsqF4v KNz06Qr1bhmOaFcUPnxx9NyxzKEwpH9l5p1u2OOGAVoMtBc0NYndeeH1GIqfHb7/Cg8K rHsunkyOFt6psYPwRusCRDS0fKYyb9MZ9TbeXwHtw2+VNuctI6+f9+wgs3Q9PGR5uyFL Nf3g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to; bh=BkGaZcU/TyX8+mo+Rq1hVlhkGHsi14KW0iVegYS4WZg=; b=ocHtPpRpKcgmQhoc/PY4ONnegjprJjR9w8uq/7OMoAH0EWKdKyBGoFMyV8iy821bwF Qyoq+xQd60wD1f0H0Fft/RNOUPCSfiCMX518VtRxlGnvDjfuTkN8QKlK/BhvoObtS3um 2/9PPXnPd0BUJjPzQdR5Ows2Js+2+5cWYt4ShATOABhRtgdzw22IZLzhMVGG5KLWOOiO A59a8rBPxdWAWcMtKwp++hQssMtx1xnCCsWsHw+9rHmDQmsXhJfCFYWMDsEnltYZUeWG 11seQHGovzRkEEC7hFipLN63yjLnyo6Laor8PUhmwReA9qJVyun5WoU3q4uwtcLVwudI 6XGw== X-Gm-Message-State: AMke39nVLA+SPg9dRbts7dZOyPZOJp1JVIqYtWXUf8BWW35/NXqZWRqkJGQG184TVprFTFaMO9CluURktaqAiw== X-Received: by 10.200.55.57 with SMTP id o54mr6733447qtb.78.1487597552528; Mon, 20 Feb 2017 05:32:32 -0800 (PST) MIME-Version: 1.0 Received: by 10.140.104.8 with HTTP; Mon, 20 Feb 2017 05:32:02 -0800 (PST) In-Reply-To: References: From: Jia-Shiun Li Date: Mon, 20 Feb 2017 21:32:02 +0800 Message-ID: Subject: Re: patching cpufreq for rpi3 To: "freebsd-arm@freebsd.org" Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.23 X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Porting FreeBSD to ARM processors." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 20 Feb 2017 13:32:34 -0000 On Wed, Feb 8, 2017 at 3:00 AM, Jia-Shiun Li wrote: > I was figuring out why frequency scaling does not work > on rpi3, and found that bcm2837 was not caught in some > cases. Thus the attached patch. > > The patch corrects voltage reporting for rpi3. > Frequency scaling still does not work though. > Any ideas? > > So, beginner pitfall #1: bad power https://www.raspberrypi.org/forums/viewtopic.php?t=83372 Make sure you have sufficient power and decent cable. Otherwise power LED will blink or even go off. The little square of rainbow or flash on top right corner of display is also indication of it. BTW you also need heatsink or fan for it to work under load and high frequency without being throttled. One thing that bothers me is on RPi3, hw.cpufreq.turbo defaults not to 0, but -1. And firmware does not limit it to 1/0, but increase/ decrease every time when set repeatedly. So in order to bump speed one actually need to set frequency or turbo twice after booting to make turbo=1. -Jia-Shiun.