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=-6.0 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 844DAC433B4 for ; Tue, 27 Apr 2021 11:39:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 672B4613E7 for ; Tue, 27 Apr 2021 11:39:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238045AbhD0LkF (ORCPT ); Tue, 27 Apr 2021 07:40:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:50520 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236100AbhD0LkE (ORCPT ); Tue, 27 Apr 2021 07:40:04 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0B2276100B; Tue, 27 Apr 2021 11:39:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1619523560; bh=TxdaOEc9CznWEwtVjOxV+KNECrQDBOoFXaJg7zjtSdU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=BzmxTy6ndGTH6LDFaqWbNZF9+4dFeqwGsI2F2JTKJGFRrfo0AW52gyJJ8oa7QjOIp uhbS67JT8WP8ZJfUgcs9wSF5ZjkjgLQx/gmIEFmFfazdPShFsCPnP4L7K8QEdGzK+R XqtTYhYmBzyO8sLQKjRjPxKRXhO1ATws16xeML5Y= Date: Tue, 27 Apr 2021 13:39:16 +0200 From: Greg KH To: Corentin Labbe Cc: rafael@kernel.org, hch@lst.de, m.szyprowski@samsung.com, robin.murphy@arm.com, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: dma-api debugfs directory is not created since debugfs is not initialized Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 27, 2021 at 01:34:27PM +0200, Corentin Labbe wrote: > Hello > > I try to debug some DMA problem on next-20210427, and so I have enabled CONFIG_DMA_API_DEBUG=y. > But the dma-api directory does show up in debugfs, but lot of other directory exists in it. Does it show up properly in 5.12? > After debugging it seems due to commit 56348560d495 ("debugfs: do not attempt to create a new file before the filesystem is initalized") > Reverting the commit permit to "dma-api" debugfs to be found. (but seems not the right way to fix it). We have had some odd start-up ordering issues that the above commit has caused to show. Given that this commit is now in stable kernels, with no report of this issue so far, I'm worried that maybe this is a dma subsystem ordering issue? thanks, greg k-h