Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752789AbcJFGFC (ORCPT ); Thu, 6 Oct 2016 02:05:02 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:38624 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752187AbcJFGFA (ORCPT ); Thu, 6 Oct 2016 02:05:00 -0400 DMARC-Filter: OpenDMARC Filter v1.3.1 smtp.codeaurora.org 1E7DB613FB Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=pass smtp.mailfrom=rnayak@codeaurora.org Message-ID: <57F5E986.40704@codeaurora.org> Date: Thu, 06 Oct 2016 11:34:54 +0530 From: Rajendra Nayak User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.0 MIME-Version: 1.0 To: Jon Hunter , "Rafael J. Wysocki" , Kevin Hilman , Ulf Hansson CC: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-tegra@vger.kernel.org Subject: Re: [RFC PATCH 0/3] PM / Domains: Add support for devices that require multiple domains References: <1474367287-10402-1-git-send-email-jonathanh@nvidia.com> In-Reply-To: <1474367287-10402-1-git-send-email-jonathanh@nvidia.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1300 Lines: 29 On 09/20/2016 03:58 PM, Jon Hunter wrote: > The Tegra124/210 XUSB subsystem (that consists of both host and device > controllers) is partitioned across 3 PM domains which are: > - XUSBA: Superspeed logic (for USB 3.0) > - XUSBB: Device controller > - XUSBC: Host controller > > These power domains are not nested and can be powered-up and down > independently of one another. In practice different scenarios require > different combinations of the power domains, for example: > - Superspeed host: XUSBA and XUSBC > - Superspeed device: XUSBA and XUSBB > > Although it could be possible to logically nest both the XUSBB and XUSBC > domains under the XUSBA, superspeed may not always be used/required and > so this would keep it on unnecessarily. Hey Jon, so does this RFC provide a way to just specify multiple Powerdomains for a device (which then will *all* be powered on/off together) or does it also provide for more granular control of these powerdomains? The above statement seems to suggest you would need more granular control of these powerdomains (like keeping XUSBA off in case superspeed it not needed) but I can't seem to figure out how you achieve it with this series. - Rajendra -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation