Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754279AbcCRTRm (ORCPT ); Fri, 18 Mar 2016 15:17:42 -0400 Received: from smtprelay4.synopsys.com ([198.182.47.9]:39190 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751865AbcCRTRk (ORCPT ); Fri, 18 Mar 2016 15:17:40 -0400 Subject: Re: [PATCH 1/2] usb: dwc3: core: Introduce dwc3_device_reinit() To: Felipe Balbi , Roger Quadros , John Youn References: <1458133551-3071-1-git-send-email-rogerq@ti.com> <1458133551-3071-2-git-send-email-rogerq@ti.com> <87r3fah8h3.fsf@intel.com> <87lh5ih6hs.fsf@intel.com> CC: , , From: John Youn Message-ID: <56EC5452.8030509@synopsys.com> Date: Fri, 18 Mar 2016 12:17:38 -0700 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <87lh5ih6hs.fsf@intel.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.10.161.111] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1625 Lines: 50 On 3/16/2016 6:56 AM, Felipe Balbi wrote: > > heh, +john > > Felipe Balbi writes: >> [ text/plain ] >> >> Hi, >> >> Roger Quadros writes: >>> [ text/plain ] >>> We will need this function for a workaround. >>> The function issues a softreset only to the device >>> controller and performs minimal re-initialization >>> so that the device controller can be usable. >>> >>> As some code is similar to dwc3_core_init() take out >>> common code into dwc3_get_gctl_quirks(). >>> >>> We add a new member (prtcap_mode) to struct dwc3 to >>> keep track of the current mode in the PRTCAPDIR register. >>> >>> Signed-off-by: Roger Quadros >> >> I must say, I don't like this at all :-p There's ONE known silicon which >> needs this because of a poor silicon integration which took an IP with a >> known erratum where it can't be made to work on lower speeds and STILL >> was integrated without a superspeed PHY. >> >> There's a reason why I never tried to push this upstream myself ;-) >> >> I'm really thinking we might be better off adding a quirk flag to skip >> the metastability workaround and allow this ONE silicon to set the >> controller to lower speed. >> >> John, can you check with your colleagues if we would ever fall into >> STAR#9000525659 if we set maximum speed to high speed during driver >> probe and never touch it again ? I would assume we don't really fall >> into the metastability workaround, right ? We're not doing any sort of >> PM for dwc3... >> Hi Felipe, I don't know much about this but I will check with the engineers and get back to you. John