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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 24FA6C433FE for ; Fri, 7 Oct 2022 13:07:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229735AbiJGNHg (ORCPT ); Fri, 7 Oct 2022 09:07:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45140 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229723AbiJGNHe (ORCPT ); Fri, 7 Oct 2022 09:07:34 -0400 Received: from radex-web.radex.nl (smtp.radex.nl [178.250.146.7]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 3DCB7C0993; Fri, 7 Oct 2022 06:07:29 -0700 (PDT) Received: from [192.168.1.35] (cust-178-250-146-69.breedbanddelft.nl [178.250.146.69]) by radex-web.radex.nl (Postfix) with ESMTPS id A76072407C; Fri, 7 Oct 2022 15:07:27 +0200 (CEST) Message-ID: Date: Fri, 7 Oct 2022 15:07:27 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.13.0 Subject: Re: [PATCH v2 2/2] Revert "usb: dwc3: Don't switch OTG -> peripheral if extcon is present" Content-Language: en-US To: Thinh Nguyen Cc: Andy Shevchenko , Greg Kroah-Hartman , Andrey Smirnov , "linux-usb@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Felipe Balbi , "stable@vger.kernel.org" References: <20220927155332.10762-1-andriy.shevchenko@linux.intel.com> <20220927155332.10762-3-andriy.shevchenko@linux.intel.com> <20221003215734.7l3cnb2zy57nrxkk@synopsys.com> <20221005021212.qwnbmq6p7t26c3a4@synopsys.com> <2886b82d-a1f6-d288-e8d1-edae54046b4f@gmail.com> <20221006021204.hz7iteao65dgsev6@synopsys.com> <20221007021122.nnwmqc6sq43e5xbn@synopsys.com> From: Ferry Toth In-Reply-To: <20221007021122.nnwmqc6sq43e5xbn@synopsys.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On 07-10-2022 04:11, Thinh Nguyen wrote: > On Thu, Oct 06, 2022, Ferry Toth wrote: >> Hi >> >> On 06-10-2022 04:12, Thinh Nguyen wrote: >>> On Wed, Oct 05, 2022, Ferry Toth wrote: >>>> Hi, >>>> >>>> Thanks! >>>> >>>> Does the failure only happen the first time host is initialized? Or can >>>> it recover after switching to device then back to host mode? >>>> >>>> I can switch back and forth and device mode works each time, host mode remains >>>> dead. >>> Ok. >>> >>>> Probably the failure happens if some step(s) in dwc3_core_init() hasn't >>>> completed. >>>> >>>> tusb1210 is a phy driver right? The issue is probably because we didn't >>>> initialize the phy yet. So, I suspect placing dwc3_get_extcon() after >>>> initializing the phy will probably solve the dependency problem. >>>> >>>> You can try something for yourself or I can provide something to test >>>> later if you don't mind (maybe next week if it's ok). >>>> >>>> Yes, the code move I mentioned above "moves dwc3_get_extcon() until after >>>> dwc3_core_init() but just before dwc3_core_init_mode(). AFAIU initially >>>> dwc3_get_extcon() was called from within dwc3_core_init_mode() but only for >>>> case USB_DR_MODE_OTG. So with this change order of events is more or less >>>> unchanged" solves the issue. >>>> >>> I saw the experiment you did from the link you provided. We want to also >>> confirm exactly which step in dwc3_core_init() was needed. >> Ok. I first tried the code move suggested by Andrey (didn't work). Then >> after reading the actual code I moved a bit further. >> >> This move was on top of -rc6 without any reverts. I did not make additional >> changes to dwc3_core_init() >> >> So current v6.0 has: dwc3_get_extcon - dwc3_get_dr_mode - ... - >> dwc3_core_init - .. - dwc3_core_init_mode (not working) >> >> I changed to: dwc3_get_dr_mode - dwc3_get_extcon - .. - dwc3_core_init - .. >> - dwc3_core_init_mode (no change) >> >> Then to: dwc3_get_dr_mode - .. - dwc3_core_init - .. - dwc3_get_extcon - >> dwc3_core_init_mode (works) >> >> .. are what I believe for this issue irrelevant calls to >> dwc3_alloc_scratch_buffers, dwc3_check_params and dwc3_debugfs_init. >> > Right. Thanks for narrowing it down. There are still many steps in > dwc3_core_init(). We have some suspicion, but we still haven't confirmed > the exact cause of the failure. We can write a proper patch once we know > the reason. If you would like me to test your suspicion, just tell me what to do :-) > > Thanks, > Thinh