From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933115AbcLHDG5 (ORCPT ); Wed, 7 Dec 2016 22:06:57 -0500 Received: from smtprelay4.synopsys.com ([198.182.47.9]:57227 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932216AbcLHDG4 (ORCPT ); Wed, 7 Dec 2016 22:06:56 -0500 Subject: Re: [PATCH 1/2] usb: dwc3: gadget: Fix full speed mode To: Felipe Balbi , Roger Quadros , John Youn References: <1480416997-19757-1-git-send-email-rogerq@ti.com> <1480416997-19757-2-git-send-email-rogerq@ti.com> <87k2bmo662.fsf@linux.intel.com> <4b44adf6-7569-71bf-b4c6-e811aeebfd1d@ti.com> <87h96flxj4.fsf@linux.intel.com> From: John Youn CC: , Message-ID: Date: Wed, 7 Dec 2016 19:06:54 -0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: <87h96flxj4.fsf@linux.intel.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.10.186.99] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/7/2016 4:44 AM, Felipe Balbi wrote: > > Hi, > > Roger Quadros writes: >>>> Roger Quadros writes: >>>>> DCFG.DEVSPD == 0x3 is not valid and we need to set >>>>> DCFG.DEVSPD to 0x1 for full speed mode. >>>> >>>> seems like it has been made invalid somewhere between 1.73a and >>>> 2.60a. Can you figure it out from Documentation why and when it was made >>>> invalid? We might need revision checks here. >>>> >>> >>> I'll try to dig out more. >> >> I couldn't figure out more information on this. The changelogs in the TRMs >> don't capture this change and I don't have access to all TRM versions >> so I can't say which version it got changed and why. >> >> Can we please involve someone from Synopsis to provide this information? >> Thanks. > > John, could you help us with this query? We'd like to understand why one > of the FULLSPEED modes got removed. Do we need a revision check or can > we assume that the other mode was never supposed to be used? > Full speed is 0x1. 0x3 may still work due to how the bits are checked. But it definitely should be 0x1. I'm not sure if it was 0x3 before. I still need to confirm whether that was the case or not and if so why. Regards, John