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,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 86CADC48BCD for ; Wed, 9 Jun 2021 18:47:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6FB0D613E6 for ; Wed, 9 Jun 2021 18:47:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229720AbhFIStS (ORCPT ); Wed, 9 Jun 2021 14:49:18 -0400 Received: from m43-7.mailgun.net ([69.72.43.7]:15555 "EHLO m43-7.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229757AbhFIStR (ORCPT ); Wed, 9 Jun 2021 14:49:17 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1623264443; h=In-Reply-To: Content-Type: MIME-Version: References: Message-ID: Subject: Cc: To: From: Date: Sender; bh=mX4L5IV5eFf/UxLYkJ4BkGaE9xSTvXZJk5GFPql7d5o=; b=T0FzTZF0C/UVXoqowvDtm2sg2vH28JhDxfS0l2zLVPDe92osT/UvGV2vaC29+b8z/LEvzbW0 4LqJmkFuwjrEfQSB+kLlCZ5M7OPEHKelUYtuLdLuRcmtkZxV+wXX8rjbH0m03nyjPzfFIsZ9 CnJmRqwBChCUVoDonb5e0Ppz1PU= 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-n07.prod.us-east-1.postgun.com with SMTP id 60c10cbae27c0cc77f017c36 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Wed, 09 Jun 2021 18:47:22 GMT Sender: jackp=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 944C8C4338A; Wed, 9 Jun 2021 18:47:21 +0000 (UTC) Received: from jackp-linux.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: jackp) by smtp.codeaurora.org (Postfix) with ESMTPSA id A5E5CC4338A; Wed, 9 Jun 2021 18:47:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org A5E5CC4338A 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=jackp@codeaurora.org Date: Wed, 9 Jun 2021 11:47:15 -0700 From: Jack Pham To: Greg Kroah-Hartman Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Felipe Balbi , Peter Chen Subject: Re: [PATCH] USB: dwc3: remove debugfs root dentry storage Message-ID: <20210609184715.GA28957@jackp-linux.qualcomm.com> References: <20210609093924.3293230-1-gregkh@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210609093924.3293230-1-gregkh@linuxfoundation.org> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Wed, Jun 09, 2021 at 11:39:24AM +0200, Greg Kroah-Hartman wrote: > There is no need to keep around the debugfs "root" directory for the > dwc3 device. Instead, look it up anytime we need to find it. This will > help when callers get out-of-order and we had the potential to have a > "stale" pointer around for the root dentry, as has happened in the past. > > Cc: Felipe Balbi > Cc: Jack Pham > Cc: Peter Chen > Signed-off-by: Greg Kroah-Hartman > --- > drivers/usb/dwc3/core.h | 2 -- > drivers/usb/dwc3/debugfs.c | 8 ++++---- > drivers/usb/dwc3/gadget.c | 4 +++- > 3 files changed, 7 insertions(+), 7 deletions(-) > > diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h > index c5d5760cdf53..dccdf13b5f9e 100644 > --- a/drivers/usb/dwc3/core.h > +++ b/drivers/usb/dwc3/core.h > @@ -1013,7 +1013,6 @@ struct dwc3_scratchpad_array { > * @link_state: link state > * @speed: device speed (super, high, full, low) > * @hwparams: copy of hwparams registers > - * @root: debugfs root folder pointer > * @regset: debugfs pointer to regdump file > * @dbg_lsp_select: current debug lsp mux register selection > * @test_mode: true when we're entering a USB test mode > @@ -1222,7 +1221,6 @@ struct dwc3 { > u8 num_eps; > > struct dwc3_hwparams hwparams; > - struct dentry *root; > struct debugfs_regset32 *regset; > > u32 dbg_lsp_select; > diff --git a/drivers/usb/dwc3/debugfs.c b/drivers/usb/dwc3/debugfs.c > index 5dbbe53269d3..f2b7675c7f62 100644 > --- a/drivers/usb/dwc3/debugfs.c > +++ b/drivers/usb/dwc3/debugfs.c > @@ -889,8 +889,10 @@ static void dwc3_debugfs_create_endpoint_files(struct dwc3_ep *dep, > void dwc3_debugfs_create_endpoint_dir(struct dwc3_ep *dep) > { > struct dentry *dir; > + struct dentry *root; > > - dir = debugfs_create_dir(dep->name, dep->dwc->root); > + root = debugfs_lookup(dev_name(dep->dwc->dev), usb_debug_root); > + dir = debugfs_create_dir(dep->name, root); > dwc3_debugfs_create_endpoint_files(dep, dir); > } > > @@ -909,8 +911,6 @@ void dwc3_debugfs_init(struct dwc3 *dwc) > dwc->regset->base = dwc->regs - DWC3_GLOBALS_REGS_START; > > root = debugfs_create_dir(dev_name(dwc->dev), usb_debug_root); > - dwc->root = root; > - > debugfs_create_regset32("regdump", 0444, root, dwc->regset); > debugfs_create_file("lsp_dump", 0644, root, dwc, &dwc3_lsp_fops); > > @@ -929,6 +929,6 @@ void dwc3_debugfs_init(struct dwc3 *dwc) > > void dwc3_debugfs_exit(struct dwc3 *dwc) > { > - debugfs_remove_recursive(dwc->root); > + debugfs_remove(debugfs_lookup(dev_name(dwc->dev), usb_debug_root)); > kfree(dwc->regset); > } > diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c > index 7cc99b6d0bfe..026a2ad0fc80 100644 > --- a/drivers/usb/dwc3/gadget.c > +++ b/drivers/usb/dwc3/gadget.c > @@ -2799,7 +2799,9 @@ static void dwc3_gadget_free_endpoints(struct dwc3 *dwc) > list_del(&dep->endpoint.ep_list); > } > > - debugfs_remove_recursive(debugfs_lookup(dep->name, dwc->root)); > + debugfs_remove_recursive(debugfs_lookup(dep->name, > + debugfs_lookup(dev_name(dep->dwc->dev), > + usb_debug_root))); Nested calls to debugfs_lookup() :). But it does work, and similarly avoids the out-of-order debugfs removal issue as well even without Peter's fix. Tested-by: Jack Pham Thanks Jack -- The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project