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=-4.0 required=3.0 tests=BAYES_00,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 F14CAC433E0 for ; Thu, 18 Feb 2021 10:19:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BD76160235 for ; Thu, 18 Feb 2021 10:19:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232650AbhBRKLX (ORCPT ); Thu, 18 Feb 2021 05:11:23 -0500 Received: from mail.kernel.org ([198.145.29.99]:47850 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231487AbhBRJF3 (ORCPT ); Thu, 18 Feb 2021 04:05:29 -0500 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5D0D66146D; Thu, 18 Feb 2021 09:04:45 +0000 (UTC) Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94) (envelope-from ) id 1lCfEp-00EjT3-Fz; Thu, 18 Feb 2021 09:04:43 +0000 Date: Thu, 18 Feb 2021 09:04:42 +0000 Message-ID: <87eehdpx05.wl-maz@kernel.org> From: Marc Zyngier To: Greg KH Cc: Michael Walle , linux-kernel@vger.kernel.org, tglx@linutronix.de Subject: Re: [PATCH] irqdomain: remove debugfs_file from struct irq_domain In-Reply-To: References: <20210217195717.13727-1-michael@walle.cc> <4e4d0479b935e60a53f75ef534086476@kernel.org> <5c527bfb6f3dfe31b5c25f29418306c6@walle.cc> <87czwys6s1.wl-maz@kernel.org> <8b4de9eae773a43b38f42c8ab6d9d23c@walle.cc> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: gregkh@linuxfoundation.org, michael@walle.cc, linux-kernel@vger.kernel.org, tglx@linutronix.de X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 18 Feb 2021 08:54:00 +0000, Greg KH wrote: [...] > > > Wow, wait, you are removing a debugfs file _before_ debugfs is even > > > initialized? Didn't expect that, ok, let me go try this again... > > > > Yeah, that's a poor man's rename (file being deleted and re-created). > > True, but that's not happening here, right? Some driver is being > initialized and creates a debugfs file, and then decides to unload so it > removes the debugfs file? No, that's not what is happening. The irqchip driver starts, creates an irqdomain. File gets created, at least in theory (it fails because debugfs isn't ready, but that's not the issue). It then changes an attribute to the domain (the so-called bus_token), which gets reflected in the domain name to avoid aliasing. Delete/create follows. > Why was it trying to create the file in the first place if it didn't > properly bind to the hardware? See above. We encode properties of the domain in the filename, and reflect the change of these properties as they happen. M. -- Without deviation from the norm, progress is not possible.