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=-15.3 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 7A676C48BE5 for ; Thu, 10 Jun 2021 18:22:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 62EC6613F5 for ; Thu, 10 Jun 2021 18:22:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231295AbhFJSYN (ORCPT ); Thu, 10 Jun 2021 14:24:13 -0400 Received: from m43-7.mailgun.net ([69.72.43.7]:22203 "EHLO m43-7.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231254AbhFJSYM (ORCPT ); Thu, 10 Jun 2021 14:24:12 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1623349335; h=Content-Transfer-Encoding: Content-Type: In-Reply-To: MIME-Version: Date: Message-ID: From: References: Cc: To: Subject: Sender; bh=E3TulAYeD48+XPfMqj2062F9NYilPaepjuhGKVCkFIg=; b=JPfDRQCRBDuXDGwl7k7WXjexphTcfqgq9faLaeSFMJ8pTTjfT2p64fBsxoK2GYVdPCoZeo9X DC03hyt4xsRYZuY9ABfohLpBKF/nYVst2i6ml6yJz1T4QxW3KfcdO1cqu0MwQ4lncQRWApSZ 2mxGFpNvvsIjP5TqaQAmNSqujro= X-Mailgun-Sending-Ip: 69.72.43.7 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-east-1.postgun.com with SMTP id 60c25842f726fa41880f020e (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Thu, 10 Jun 2021 18:21:54 GMT Sender: wcheng=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 3C694C4360C; Thu, 10 Jun 2021 18:21:53 +0000 (UTC) Received: from [10.110.62.3] (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 4B639C433D3; Thu, 10 Jun 2021 18:21:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 4B639C433D3 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: Disable gadget IRQ during pullup disable To: Felipe Balbi , gregkh@linuxfoundation.org Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, jackp@codeaurora.org References: <1621571037-1424-1-git-send-email-wcheng@codeaurora.org> <87h7i60ye8.fsf@kernel.org> From: Wesley Cheng Message-ID: <724ba69a-8c67-4b4b-3e6a-a5834b09e6e1@codeaurora.org> Date: Thu, 10 Jun 2021 11:21:51 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.10.2 MIME-Version: 1.0 In-Reply-To: <87h7i60ye8.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 6/10/2021 4:09 AM, Felipe Balbi wrote: > Wesley Cheng writes: > >> Current sequence utilizes dwc3_gadget_disable_irq() alongside >> synchronize_irq() to ensure that no further DWC3 events are generated. >> However, the dwc3_gadget_disable_irq() API only disables device >> specific events. Endpoint events can still be generated. Briefly >> disable the interrupt line, so that the cleanup code can run to >> prevent device and endpoint events. (i.e. __dwc3_gadget_stop() and >> dwc3_stop_active_transfers() respectively) >> >> Without doing so, it can lead to both the interrupt handler and the >> pullup disable routine both writing to the GEVNTCOUNT register, which >> will cause an incorrect count being read from future interrupts. >> >> Fixes: ae7e86108b12 ("usb: dwc3: Stop active transfers before halting the controller") >> Signed-off-by: Wesley Cheng >> --- >> drivers/usb/dwc3/gadget.c | 11 +++++------ >> 1 file changed, 5 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c >> index 49ca5da..89aa9ac 100644 >> --- a/drivers/usb/dwc3/gadget.c >> +++ b/drivers/usb/dwc3/gadget.c >> @@ -2260,13 +2260,10 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on) >> } >> >> /* >> - * Synchronize any pending event handling before executing the controller >> - * halt routine. >> + * Synchronize and disable any further event handling while controller >> + * is being enabled/disabled. >> */ >> - if (!is_on) { >> - dwc3_gadget_disable_irq(dwc); >> - synchronize_irq(dwc->irq_gadget); >> - } >> + disable_irq(dwc->irq_gadget); >> >> spin_lock_irqsave(&dwc->lock, flags); > > spin_lock_irqsave() is already disabling interrupt, right? Why do we > need another call to disable_irq()? > Hi Felipe, Yes, I remember you brought up that point as well before. So when I checked the logs (USB and scheduler ftrace) for this issue, I clearly saw that we were handling a soft disconnect on CPU3 and then an DWC3 IRQ being scheduled into CPU0. Last time we discussed, I mentioned that spin_lock_irqsave() only disables interrupts on that particular CPU the thread is running on. Thanks Wesley Cheng -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project