From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753790AbeE3S1c (ORCPT ); Wed, 30 May 2018 14:27:32 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:49074 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753526AbeE3S13 (ORCPT ); Wed, 30 May 2018 14:27:29 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 5AE106038E Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=collinsd@codeaurora.org Subject: Re: [PATCH v2 1/6] soc: qcom: rpmpd: Add a powerdomain driver to model corners To: Rajendra Nayak , Ulf Hansson Cc: Viresh Kumar , Stephen Boyd , Andy Gross , devicetree@vger.kernel.org, linux-arm-msm , Linux Kernel Mailing List References: <20180525100121.28214-1-rnayak@codeaurora.org> <20180525100121.28214-2-rnayak@codeaurora.org> <0e07d577-9728-e97a-2da0-dd7dd324f058@codeaurora.org> From: David Collins Message-ID: <7432f626-69cd-3535-04bc-de42e0285d41@codeaurora.org> Date: Wed, 30 May 2018 11:27:27 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.1.1 MIME-Version: 1.0 In-Reply-To: <0e07d577-9728-e97a-2da0-dd7dd324f058@codeaurora.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Rajendra, On 05/30/2018 03:14 AM, Rajendra Nayak wrote: > On 05/30/2018 02:47 PM, Ulf Hansson wrote: >> On 25 May 2018 at 12:01, Rajendra Nayak wrote: ... >>> + pm_genpd_init(&rpmpds[i]->pd, NULL, true); >> >> Question: Is there no hierarchical topology of the PM domains. No >> genpd subdomains? > > The hierarchy if any is all handled by the remote core (RPM in this case). > For Linux its just a flat view. There is one special case that we'll need to handle somehow. The APPS vlvl request for VDD_MX needs to be greater than or equal to the vlvl request for VDD_CX. Can you please add the necessary code to achieve this? RPMh hardware doesn't handle this hardware requirement due to concerns about modem use case latency. Please note that this is handled in a somewhat hacky manner [1] with the downstream rpmh-regulator driver by specifying VDD_MX as the parent of VDD_CX and VDD_MX_AO as the parent of VDD_CX_AO with a dropout voltage of -1. That way, enabling CX causes MX to be enabled and voltage level requests are propagated from CX to MX (the -1 is ignored because it is rounded up within the sparse vlvl numbering space). Thanks, David [1]: https://source.codeaurora.org/quic/la/kernel/msm-4.9/tree/arch/arm64/boot/dts/qcom/sdm845-regulator.dtsi?h=msm-4.9#n135 -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project