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=-15.4 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, 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 C6469C432BE for ; Wed, 4 Aug 2021 06:19:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9F9E460F25 for ; Wed, 4 Aug 2021 06:19:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235519AbhHDGTm (ORCPT ); Wed, 4 Aug 2021 02:19:42 -0400 Received: from so254-9.mailgun.net ([198.61.254.9]:14498 "EHLO so254-9.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234500AbhHDGTm (ORCPT ); Wed, 4 Aug 2021 02:19:42 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1628057970; h=Content-Transfer-Encoding: Content-Type: In-Reply-To: MIME-Version: Date: Message-ID: From: References: Cc: To: Subject: Sender; bh=MvT690lgnJQyLYZVI6U25Gaz7oGo0Bzcm+74dXOx2iY=; b=WHMbG/5ofgFeOo1NH6/F1H+B4DtcRfoo8i1JhH5KxG4vgXBiZ0JZjRCjdahgGvwmI5kpANdy +VNKuyw2JAEy95epmg2IQCU8xTuL3nTnc+bpsjsX6paNrwx3IqCSvVRL6kq1EmznyxH3GnNL OqCpmDVyiTQkJHLIWq5tp+VDM8M= X-Mailgun-Sending-Ip: 198.61.254.9 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-n01.prod.us-east-1.postgun.com with SMTP id 610a31703341038a23603d7e (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Wed, 04 Aug 2021 06:19:28 GMT Sender: wcheng=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 06D47C4338A; Wed, 4 Aug 2021 06:19:28 +0000 (UTC) Received: from [192.168.1.9] (cpe-75-80-185-151.san.res.rr.com [75.80.185.151]) (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 C3E02C433F1; Wed, 4 Aug 2021 06:19:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org C3E02C433F1 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] usb: dwc3: gadget: Avoid runtime resume if disabling pullup To: Felipe Balbi , Jack Pham Cc: gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org References: <1627691374-15711-1-git-send-email-wcheng@codeaurora.org> <20210802213301.GG25299@jackp-linux.qualcomm.com> <87tuk7558p.fsf@kernel.org> From: Wesley Cheng Message-ID: Date: Tue, 3 Aug 2021 23:19:25 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <87tuk7558p.fsf@kernel.org> 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 8/3/2021 12:58 AM, Felipe Balbi wrote: > > Jack Pham writes: > >> Hi Wesley, >> >> On Fri, Jul 30, 2021 at 05:29:34PM -0700, Wesley Cheng wrote: >>> If the device is already in the runtime suspended state, any call to >>> the pullup routine will issue a runtime resume on the DWC3 core >>> device. If the USB gadget is disabling the pullup, then avoid having >>> to issue a runtime resume, as DWC3 gadget has already been >>> halted/stopped. >>> >>> This fixes an issue where the following condition occurs: >>> >>> usb_gadget_remove_driver() >>> -->usb_gadget_disconnect() >>> -->dwc3_gadget_pullup(0) >>> -->pm_runtime_get_sync() -> ret = 0 >>> -->pm_runtime_put() [async] >>> -->usb_gadget_udc_stop() >>> -->dwc3_gadget_stop() >>> -->dwc->gadget_driver = NULL >>> ... >>> >>> dwc3_suspend_common() >>> -->dwc3_gadget_suspend() >>> -->DWC3 halt/stop routine skipped, driver_data == NULL >>> >>> This leads to a situation where the DWC3 gadget is not properly >>> stopped, as the runtime resume would have re-enabled EP0 and event >>> interrupts, and since we avoided the DWC3 gadget suspend, these >>> resources were never disabled. >>> >>> Signed-off-by: Wesley Cheng >>> --- >>> drivers/usb/dwc3/gadget.c | 11 +++++++++++ >>> 1 file changed, 11 insertions(+) >>> >>> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c >>> index a29a4ca..5d08454 100644 >>> --- a/drivers/usb/dwc3/gadget.c >>> +++ b/drivers/usb/dwc3/gadget.c >>> @@ -2435,6 +2435,17 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on) >>> } >>> >>> /* >>> + * Avoid issuing a runtime resume if the device is already in the >>> + * suspended state during gadget disconnect. DWC3 gadget was already >>> + * halted/stopped during runtime suspend. >>> + */ >>> + if (!is_on) { >>> + pm_runtime_barrier(dwc->dev); >>> + if (pm_runtime_suspended(dwc->dev)) >>> + return 0; >>> + } >>> + >>> + /* >>> * Check the return value for successful resume, or error. For a >>> * successful resume, the DWC3 runtime PM resume routine will handle >>> * the run stop sequence, so avoid duplicate operations here. Hi Jack/Felipe, >> >> Should this also go to stable with Fixes: 77adb8bdf422 ("usb: dwc3: >> gadget: Allow runtime suspend if UDC unbinded") ? > > sounds like a good idea. > Sure, will update the commit text with the fixes tag. Thanks! Regards, Wesley Cheng -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project