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=-5.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_MUTT 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 30436C48BD6 for ; Wed, 26 Jun 2019 02:35:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F2C1C2085A for ; Wed, 26 Jun 2019 02:35:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kroah.com header.i=@kroah.com header.b="JiKHurGt"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="BoDp4+mD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726653AbfFZCfY (ORCPT ); Tue, 25 Jun 2019 22:35:24 -0400 Received: from out5-smtp.messagingengine.com ([66.111.4.29]:52821 "EHLO out5-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726376AbfFZCfY (ORCPT ); Tue, 25 Jun 2019 22:35:24 -0400 Received: from compute6.internal (compute6.nyi.internal [10.202.2.46]) by mailout.nyi.internal (Postfix) with ESMTP id 1B1C6214DB; Tue, 25 Jun 2019 22:35:23 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute6.internal (MEProxy); Tue, 25 Jun 2019 22:35:23 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kroah.com; h= date:from:to:cc:subject:message-id:references:mime-version :content-type:in-reply-to; s=fm1; bh=jIHvX6C3uy/LO1APr38oWz1pKsZ oM8Lka5+8kS66nWo=; b=JiKHurGtVB14zeUNzn6zusvJbkfDl4zZ7gHTCVCPgyF lmtPvIWG9MNDCtedgeTO9bK8axCY3FhOmb884OJRQGUAZnjUqPXVVoxqWwsTrIXX UHN6RLu/Y89vc7U+Nx+J2IXfQr0IWuhCAu5O3PM1foeKYooPEVcICqFtOWpXGpFN ayGDKkHYwK6RxnEW8jzPUTgFBHSSKvAjmdxh541W4zQfur8dn3CXcgLHxLR6+ItT zGr+GTonNjRInJAcJWfxFHE2YUd1PPjzjlaYp4ze9bzK8+xO4hnFUdF66qX8bGeP BW/Mwf9Q/kXNe4Q5ZuWINt6tWKdYBmxCTXvtZz0+7jA== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm3; bh=jIHvX6 C3uy/LO1APr38oWz1pKsZoM8Lka5+8kS66nWo=; b=BoDp4+mDPdqDUMkIwqElb1 2N86hc/xv98WbdIt3V4MCHTD/JEtLctKxZuXboe3zVKjVgxuutO1PBg2Tja1nBLt 95LxLrR9bKzp9Zq4po5sz8y9f2rKKbGOiviy1wsIq08ovKUmEjrxNHHN6aeAlRIc JVDKutNFBZ00AxEQINYcoxSTv7xrMvTiDwzPjD1ATbEoSNpTY2/1AWHYwpmcqPq1 MUjG5GAPyuBj6N1kNaj6YCHrxDE1MKfdoKax+n6m2z3SMy6JpyafvofRBNe8YS6+ yuPde0mRcv2AT/VS9dxF78dgMdNrgpUbBowjZ5SQO9k/xPiX8Db332JpCTqksidw == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduvddrudehgdehjecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenuc fjughrpeffhffvuffkfhggtggujggfsehttdertddtredvnecuhfhrohhmpefirhgvghcu mffjuceoghhrvghgsehkrhhorghhrdgtohhmqeenucfkphepudejvddruddtgedrvdegke drgeegnecurfgrrhgrmhepmhgrihhlfhhrohhmpehgrhgvgheskhhrohgrhhdrtghomhen ucevlhhushhtvghrufhiiigvpedt X-ME-Proxy: Received: from localhost (li1825-44.members.linode.com [172.104.248.44]) by mail.messagingengine.com (Postfix) with ESMTPA id 66FA18005A; Tue, 25 Jun 2019 22:35:19 -0400 (EDT) Date: Wed, 26 Jun 2019 10:30:58 +0800 From: Greg KH To: Alan Stern Cc: USB list Subject: Re: [PATCH] USB: core: Remove usbfs_mutex Message-ID: <20190626023058.GA18819@kroah.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.1 (2019-06-15) Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Tue, Jun 25, 2019 at 04:03:58PM -0400, Alan Stern wrote: > Commit 4a2a8a2cce86 ("usbfs: private mutex for open, release, and > remove") is now obsolete. The commit was created back when we had > to handle both usbfs device nodes and the old usbdevfs filesystem > (/proc/bus/usb/), but usbdevfs no longer exists. > > This means there's no longer any need to hold a mutex during two > separate removal operations (and thus during an entire notifier chain > call). Furthermore, the one remaining remove/release pair doesn't > race with open thanks to the synchronization provided by the device > model core in bus_find_device(). Remove and release don't race with > each other because they both run with the device lock held. > > The upshot is that usbfs_mutex isn't needed any more. This patch > removes it entirely. > > Signed-off-by: Alan Stern > Ah, nice, I forgot all about this mutex, thanks for removing it! greg k-h