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=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 3BF31C433E0 for ; Tue, 30 Mar 2021 09:56:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 067F6619A9 for ; Tue, 30 Mar 2021 09:56:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231426AbhC3J4P (ORCPT ); Tue, 30 Mar 2021 05:56:15 -0400 Received: from m43-7.mailgun.net ([69.72.43.7]:51611 "EHLO m43-7.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231719AbhC3J4B (ORCPT ); Tue, 30 Mar 2021 05:56:01 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1617098160; h=Message-ID: References: In-Reply-To: Subject: Cc: To: From: Date: Content-Transfer-Encoding: Content-Type: MIME-Version: Sender; bh=kZkHy+TZAIF7RJSqiEdvPgs5x2iX75AYeXHJhVDx5x8=; b=Zbx0Yrwa+I0q+nlzpNMVwOJ1Aupui5sipfGKEp7e/hivSSv6ptM3A6TeydNH4rSA1DeRZysh /lzu4psmY2nriJSXgs2+xyiVJkBGTiTSZLZJcBVhONT1Wb+iiKDmznvDkhuUvao+0/+KBC8f UVPoo4EyY9JysJnhLSN9imYZVsQ= X-Mailgun-Sending-Ip: 69.72.43.7 X-Mailgun-Sid: WyIxZTE2YSIsICJsaW51eC11c2JAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n02.prod.us-east-1.postgun.com with SMTP id 6062f5b00a4a07ffda6603ff (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Tue, 30 Mar 2021 09:56:00 GMT Sender: saiprakash.ranjan=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 92F4AC433C6; Tue, 30 Mar 2021 09:55:59 +0000 (UTC) Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: saiprakash.ranjan) by smtp.codeaurora.org (Postfix) with ESMTPSA id CFFB7C433ED; Tue, 30 Mar 2021 09:55:58 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Tue, 30 Mar 2021 15:25:58 +0530 From: Sai Prakash Ranjan To: Greg Kroah-Hartman Cc: Sandeep Maheswaram , Felipe Balbi , Stephen Boyd , Doug Anderson , Matthias Kaehlcke , linux-arm-msm@vger.kernel.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Manu Gautam Subject: Re: [PATCH v1] usb: dwc3: core: Add shutdown callback for dwc3 In-Reply-To: References: <1616527652-7937-1-git-send-email-sanm@codeaurora.org> Message-ID: X-Sender: saiprakash.ranjan@codeaurora.org User-Agent: Roundcube Webmail/1.3.9 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On 2021-03-30 14:37, Greg Kroah-Hartman wrote: > On Tue, Mar 30, 2021 at 02:12:04PM +0530, Sandeep Maheswaram wrote: >> >> On 3/26/2021 7:07 PM, Greg Kroah-Hartman wrote: >> > On Wed, Mar 24, 2021 at 12:57:32AM +0530, Sandeep Maheswaram wrote: >> > > This patch adds a shutdown callback to USB DWC core driver to ensure that >> > > it is properly shutdown in reboot/shutdown path. This is required >> > > where SMMU address translation is enabled like on SC7180 >> > > SoC and few others. If the hardware is still accessing memory after >> > > SMMU translation is disabled as part of SMMU shutdown callback in >> > > system reboot or shutdown path, then IOVAs(I/O virtual address) >> > > which it was using will go on the bus as the physical addresses which >> > > might result in unknown crashes (NoC/interconnect errors). >> > > >> > > Previously this was added in dwc3 qcom glue driver. >> > > https://patchwork.kernel.org/project/linux-arm-msm/list/?series=382449 >> > > But observed kernel panic as glue driver shutdown getting called after >> > > iommu shutdown. As we are adding iommu nodes in dwc core node >> > > in device tree adding shutdown callback in core driver seems correct. >> > So shouldn't you also remove this from the qcom glue driver at the same >> > time? Please submit both as a patch series. >> > >> > thanks, >> > >> > greg k-h >> >> Hi Greg, >> >> The qcom glue driver patch is not merged yet. I have just mentioned >> for it for reference. > > You know that we can not add callbacks for no in-kernel user, so what > good is this patch for now? > What in-kernel user? Since when does shutdown callback need an in-kernel user? When you reboot or shutdown a system, it gets called. The reason why the shutdown callback is needed is provided in the commit text. Confused, Sai Prakash Ranjan -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation