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 X-Spam-Level: X-Spam-Status: No, score=-9.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_NEOMUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BC032C10F11 for ; Wed, 24 Apr 2019 05:33:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8BFDA2089F for ; Wed, 24 Apr 2019 05:33:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="BFtXtKdN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729487AbfDXFdd (ORCPT ); Wed, 24 Apr 2019 01:33:33 -0400 Received: from mail-pf1-f195.google.com ([209.85.210.195]:45436 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729430AbfDXFdc (ORCPT ); Wed, 24 Apr 2019 01:33:32 -0400 Received: by mail-pf1-f195.google.com with SMTP id e24so8656654pfi.12 for ; Tue, 23 Apr 2019 22:33:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=ob8NZIMWaFUbrMN0tZ9gmnARtUfEz968OW1qZEZY2U4=; b=BFtXtKdNBVOTmiRT98kXDkwNylNrAtarZZ72c4GYQf9yqm8ueePojjS2zoX96t1GKh EnxlIDMB4SRPew1+0c3OOkEGorRERK7Fc8CwYvYVmqjx12r20CBqGmvme9nUMZlFmjgb SEtnC2VCvBR1UtBRcr518054JOY4LQwZ22DwrxfFDX49UEP32WgS6Pf1BBo19u8XxVlO yi3Pby6oATUW3PKT86xKmmCBhEUmFlmQp5rc/9qGpm7l8+h9EAsvwPW9fGr40NgeYGI4 sD35MnfsLiUtjbncsW8dGQAjKEkbcegE+SIWv2SqlAi2Wa+NR5laj09ptg87N9XkQ8UF FqMw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=ob8NZIMWaFUbrMN0tZ9gmnARtUfEz968OW1qZEZY2U4=; b=hc08rkoTO6DIVy/YvKyE1sDZDTY82COYzyqb5k67iSTMIW9DwheefOWKREe9pfghAW V4YZ110wr2ZE+1KjOmUU0mpDoexrH5+6Fe/S7ojcKX7LivdHqyVd73lHeAeDOkdDeRQ3 w40UHzB6ppzCBH+kysM82CMo187diFLQZ860+um3E46UTiP0i9iNTY0GRLA9C1Jvzuq1 RQ/gxUVmyExk/wkyRtt/NLkIMzZ4XC+Q+FjtKncaRypP3tCcm4okTaYHW9qH83J66jLf AM9Zkn1O1l6B1iMctvcRAdee6tL8B4bVKbs3DCnD581u+YR5Z3fxCt3QtZ2+3YOPG46d 4Rbw== X-Gm-Message-State: APjAAAUZc7AoVhOTcqfYOw0nWQyhURc3YVz3MKTyGou6vq2Y3Eo2KU5+ hplCWOAX0wkHbgGnqhHNfM2xMg== X-Google-Smtp-Source: APXvYqw83oLMfwekpoQ9cPC0MfACeIv8F95gDyBz44UEMQI/DhbKAdZHV1x1T8t0e5Zxjz57NnnJPQ== X-Received: by 2002:a63:2b41:: with SMTP id r62mr28865997pgr.403.1556084011223; Tue, 23 Apr 2019 22:33:31 -0700 (PDT) Received: from localhost ([122.166.139.136]) by smtp.gmail.com with ESMTPSA id h127sm25296392pgc.31.2019.04.23.22.33.29 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 23 Apr 2019 22:33:29 -0700 (PDT) Date: Wed, 24 Apr 2019 11:03:27 +0530 From: Viresh Kumar To: Georgi Djakov Cc: vireshk@kernel.org, sboyd@kernel.org, nm@ti.com, robh+dt@kernel.org, mark.rutland@arm.com, rjw@rjwysocki.net, jcrouse@codeaurora.org, vincent.guittot@linaro.org, bjorn.andersson@linaro.org, amit.kucheria@linaro.org, seansw@qti.qualcomm.com, daidavid1@codeaurora.org, evgreen@chromium.org, sibis@codeaurora.org, linux-pm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org Subject: Re: [PATCH v2 1/5] dt-bindings: opp: Introduce bandwidth-MBps bindings Message-ID: <20190424053327.xatmhs3hx62c7tn5@vireshk-i7> References: <20190423132823.7915-1-georgi.djakov@linaro.org> <20190423132823.7915-2-georgi.djakov@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190423132823.7915-2-georgi.djakov@linaro.org> User-Agent: NeoMutt/20180323-120-3dd1ac Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 23-04-19, 16:28, Georgi Djakov wrote: > In addition to frequency and voltage, some devices may have bandwidth > requirements for their interconnect throughput - for example a CPU > or GPU may also need to increase or decrease their bandwidth to DDR > memory based on the current operating performance point. > > Extend the OPP tables with additional property to describe the bandwidth > needs of a device. The average and peak bandwidth values depend on the > hardware and its properties. > > Signed-off-by: Georgi Djakov > --- > Documentation/devicetree/bindings/opp/opp.txt | 38 +++++++++++++++++++ > .../devicetree/bindings/property-units.txt | 4 ++ > 2 files changed, 42 insertions(+) > > diff --git a/Documentation/devicetree/bindings/opp/opp.txt b/Documentation/devicetree/bindings/opp/opp.txt > index 76b6c79604a5..830f0206aea7 100644 > --- a/Documentation/devicetree/bindings/opp/opp.txt > +++ b/Documentation/devicetree/bindings/opp/opp.txt > @@ -132,6 +132,9 @@ Optional properties: > - opp-level: A value representing the performance level of the device, > expressed as a 32-bit integer. > > +- bandwidth-MBps: The interconnect bandwidth is specified with an array containing > + the two integer values for average and peak bandwidth in megabytes per second. > + > - clock-latency-ns: Specifies the maximum possible transition latency (in > nanoseconds) for switching to this OPP from any other OPP. > > @@ -546,3 +549,38 @@ Example 6: opp-microvolt-, opp-microamp-: > }; > }; > }; > + > +Example 7: bandwidth-MBps: > +Average and peak bandwidth values for the interconnects between CPU and DDR > +memory and also between CPU and L3 are defined per each OPP. Bandwidth of both > +interconnects is scaled together with CPU frequency. > + > +/ { > + cpus { > + CPU0: cpu@0 { > + compatible = "arm,cortex-a53", "arm,armv8"; > + ... > + operating-points-v2 = <&cpu_opp_table>; > + /* path between CPU and DDR memory and CPU and L3 */ > + interconnects = <&noc MASTER_CPU &noc SLAVE_DDR>, > + <&noc MASTER_CPU &noc SLAVE_L3>; > + }; > + }; > + > + cpu_opp_table: cpu_opp_table { > + compatible = "operating-points-v2"; > + opp-shared; > + > + opp-200000000 { > + opp-hz = /bits/ 64 <200000000>; > + /* CPU<->DDR bandwidth: 457 MB/s average, 1525 MB/s peak */ > + * CPU<->L3 bandwidth: 914 MB/s average, 3050 MB/s peak */ > + bandwidth-MBps = <457 1525>, <914 3050>; > + }; > + opp-400000000 { > + opp-hz = /bits/ 64 <400000000>; > + /* CPU<->DDR bandwidth: 915 MB/s average, 3051 MB/s peak */ > + * CPU<->L3 bandwidth: 1828 MB/s average, 6102 MB/s peak */ > + bandwidth-MBps = <915 3051>, <1828 6102>; > + }; > + }; > diff --git a/Documentation/devicetree/bindings/property-units.txt b/Documentation/devicetree/bindings/property-units.txt > index bfd33734faca..9c3dbefcdae8 100644 > --- a/Documentation/devicetree/bindings/property-units.txt > +++ b/Documentation/devicetree/bindings/property-units.txt > @@ -41,3 +41,7 @@ Temperature > Pressure > ---------------------------------------- > -kpascal : kiloPascal > + > +Throughput > +---------------------------------------- > +-MBps : megabytes per second LGTM -- viresh