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 X-Spam-Level: X-Spam-Status: No, score=-10.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A45A4C433E0 for ; Sat, 6 Mar 2021 09:05:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7E97D65019 for ; Sat, 6 Mar 2021 09:05:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230052AbhCFJE1 (ORCPT ); Sat, 6 Mar 2021 04:04:27 -0500 Received: from z11.mailgun.us ([104.130.96.11]:29725 "EHLO z11.mailgun.us" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229628AbhCFJEN (ORCPT ); Sat, 6 Mar 2021 04:04:13 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1615021453; h=Content-Transfer-Encoding: Content-Type: In-Reply-To: MIME-Version: Date: Message-ID: From: References: Cc: To: Subject: Sender; bh=QO3yPqzvtDZ9RjENPYRAVbzJD3mYDqyCSyxNAHWUCHM=; b=WiCNoslBxJqzQ4r53WAAuCSUxSwFolEFQs2F+o2Ft6y/FpWAKOfDSQ2g/d7KoPBxLq6uIl+7 d5KcJcYrMA5M7+Qq4+lJhaFBO97t6FD2U8RrOWh1sHSlRq9yFf2288KsamLJPgqSA0vrogct +xtKkeOpS0ILn+scH1w0cQnSwfs= X-Mailgun-Sending-Ip: 104.130.96.11 X-Mailgun-Sid: WyI0MWYwYSIsICJsaW51eC1rZXJuZWxAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n06.prod.us-west-2.postgun.com with SMTP id 604345862a5e6d1bfa4e796f (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Sat, 06 Mar 2021 09:04:06 GMT Sender: wcheng=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 4C577C43466; Sat, 6 Mar 2021 09:04:06 +0000 (UTC) Received: from [10.110.25.174] (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: wcheng) by smtp.codeaurora.org (Postfix) with ESMTPSA id D64F6C433C6; Sat, 6 Mar 2021 09:04:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org D64F6C433C6 Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=fail smtp.mailfrom=wcheng@codeaurora.org Subject: Re: [PATCH v3 1/2] usb: dwc3: Trigger a GCTL soft reset when switching modes in DRD To: Thinh Nguyen , John Stultz , Felipe Balbi Cc: lkml , Yu Chen , Tejas Joglekar , Yang Fei , YongQin Liu , Andrzej Pietrasiewicz , Jun Li , Mauro Carvalho Chehab , Greg Kroah-Hartman , Linux USB List , Heikki Krogerus , Roger Quadros References: <20210108015115.27920-1-john.stultz@linaro.org> <87bldzwr6x.fsf@kernel.org> From: Wesley Cheng Message-ID: <06a44245-4f2f-69ba-fe46-b88a19f585c2@codeaurora.org> Date: Sat, 6 Mar 2021 01:04:01 -0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/8/2021 4:44 PM, Thinh Nguyen wrote: > Hi, > > John Stultz wrote: >> On Fri, Jan 8, 2021 at 4:26 AM Felipe Balbi wrote: >>> >>> Hi, >>> >>> John Stultz writes: >>>> From: Yu Chen >>>> >>>> Just resending this, as discussion died out a bit and I'm not >>>> sure how to make further progress. See here for debug data that >>>> was requested last time around: >>>> https://urldefense.com/v3/__https://lore.kernel.org/lkml/CALAqxLXdnaUfJKx0aN9xWwtfWVjMWigPpy2aqsNj56yvnbU80g@mail.gmail.com/__;!!A4F2R9G_pg!LNzuprAeg-O80SgolYkIkW4-ne-M-yLWCDUY9MygAIrQC398Z6gRJ9wnsnlqd3w$ >>>> >>>> With the current dwc3 code on the HiKey960 we often see the >>>> COREIDLE flag get stuck off in __dwc3_gadget_start(), which >>>> seems to prevent the reset irq and causes the USB gadget to >>>> fail to initialize. >>>> >>>> We had seen occasional initialization failures with older >>>> kernels but with recent 5.x era kernels it seemed to be becoming >>>> much more common, so I dug back through some older trees and >>>> realized I dropped this quirk from Yu Chen during upstreaming >>>> as I couldn't provide a proper rational for it and it didn't >>>> seem to be necessary. I now realize I was wrong. >>>> >>>> After resubmitting the quirk, Thinh Nguyen pointed out that it >>>> shouldn't be a quirk at all and it is actually mentioned in the >>>> programming guide that it should be done when switching modes >>>> in DRD. >>>> >>>> So, to avoid these !COREIDLE lockups seen on HiKey960, this >>>> patch issues GCTL soft reset when switching modes if the >>>> controller is in DRD mode. >>>> >>>> Cc: Felipe Balbi >>>> Cc: Tejas Joglekar >>>> Cc: Yang Fei >>>> Cc: YongQin Liu >>>> Cc: Andrzej Pietrasiewicz >>>> Cc: Thinh Nguyen >>>> Cc: Jun Li >>>> Cc: Mauro Carvalho Chehab >>>> Cc: Greg Kroah-Hartman >>>> Cc: linux-usb@vger.kernel.org >>>> Signed-off-by: Yu Chen >>>> Signed-off-by: John Stultz >>>> --- >>>> v2: >>>> * Rework to always call the GCTL soft reset in DRD mode, >>>> rather then using a quirk as suggested by Thinh Nguyen >>>> >>>> v3: >>>> * Move GCTL soft reset under the spinlock as suggested by >>>> Thinh Nguyen >>> Because this is such an invasive change, I would prefer that we get >>> Tested-By tags from a good fraction of the users before applying these >>> two changes. >> I'm happy to reach out to folks to try to get that. Though I'm >> wondering if it would be better to put it behind a dts quirk flag, as >> originally proposed? >> https://urldefense.com/v3/__https://lore.kernel.org/lkml/20201021181803.79650-1-john.stultz@linaro.org/__;!!A4F2R9G_pg!LNzuprAeg-O80SgolYkIkW4-ne-M-yLWCDUY9MygAIrQC398Z6gRJ9wnRWITZfc$ >> >> That way folks can enable it for devices as they need? >> >> Again, I'm not trying to force this in as-is, just mostly sending it >> out again for discussion to understand what other approach might work. >> >> thanks >> -john > > A quirk would imply something is broken/diverged from the design right? > But it's not the case here, and at least this is needed for HiKey960. > Also, I think Rob will be ok with not adding 1 more quirk to the dwc3 > devicetree. :) > > BR, > Thinh > Hi All, Sorry for jumping in, but I checked the SNPS v1.90a databook, and that seemed to remove the requirement for the GCTL.softreset before writing to PRTCAPDIR. Should we consider adding a controller version/IP check? Thanks Wesley Cheng -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project