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=-5.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 ECFD9C43461 for ; Thu, 8 Apr 2021 07:29:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C314060FF1 for ; Thu, 8 Apr 2021 07:29:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230014AbhDHHaC (ORCPT ); Thu, 8 Apr 2021 03:30:02 -0400 Received: from mail.kernel.org ([198.145.29.99]:52104 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229623AbhDHHaA (ORCPT ); Thu, 8 Apr 2021 03:30:00 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3436E61104; Thu, 8 Apr 2021 07:29:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1617866989; bh=AQnzc2cyjD+0otvwMhgDKob+JrmQbJnn7quJBoek+yM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=L0CatQJVypkmSBw+4BFdAF6HiRJAOZwqq4GsiVZ4flVTqr2tmdPRCJr9/lVSyDWv7 kdernQc6wnYM8NaLRBhmEovMpQCxeC67OTU7amO6FVdyeANjC8dDrGzU9H+eXx/X58 qvHK3t53M7dTrDkzf3DjaQfCwJTylPmf4+K7hkS4= Date: Thu, 8 Apr 2021 09:29:46 +0200 From: Greg Kroah-Hartman To: Sandeep Maheswaram Cc: Sai Prakash Ranjan , 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 Message-ID: References: <1616527652-7937-1-git-send-email-sanm@codeaurora.org> <7f67d898-2b04-8e38-a945-5a717d1ce8c4@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7f67d898-2b04-8e38-a945-5a717d1ce8c4@codeaurora.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 08, 2021 at 10:22:57AM +0530, Sandeep Maheswaram wrote: > > On 3/30/2021 7:02 PM, Greg Kroah-Hartman wrote: > > On Tue, Mar 30, 2021 at 06:18:43PM +0530, Sai Prakash Ranjan wrote: > > > On 2021-03-30 16:46, Greg Kroah-Hartman wrote: > > > > On Tue, Mar 30, 2021 at 03:25:58PM +0530, Sai Prakash Ranjan wrote: > > > > > 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. > > > > As I can't see the patch here, I have no idea... > > > You are replying now to the same patch which adds this shutdown callback :) > > > Anyways the qcom dwc3 driver patch which is abandoned which is also > > > mentioned > > > in the commit text is here [1] and the new shutdown callback patch which we > > > are both replying to is in here [2] > > > > > > [1] https://lore.kernel.org/lkml/1605162619-10064-1-git-send-email-sanm@codeaurora.org/ > > > > > > [2] https://lore.kernel.org/lkml/1616527652-7937-1-git-send-email-sanm@codeaurora.org/ > > Thanks, so, what am I supposed to do here? The patch is long gone from > > my queue... > > > > greg k-h > > Hi Greg, > > Should I resend this patch ? If so let me know your about opinion about > Stephen's comment on just calling dwc3_remove in > > dwc3_shutdown and ignoring return value. > > https://lore.kernel.org/patchwork/patch/1401242/#1599316 Please resend as again, it's not in my queue of patches to review at all... And yes, Stephen's comment does make sense, why ignore that? thanks, greg k-h