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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable 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 E9893C54FCE for ; Mon, 23 Mar 2020 17:31:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CB64720722 for ; Mon, 23 Mar 2020 17:31:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727558AbgCWRa7 (ORCPT ); Mon, 23 Mar 2020 13:30:59 -0400 Received: from mx2.suse.de ([195.135.220.15]:38176 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727361AbgCWRa7 (ORCPT ); Mon, 23 Mar 2020 13:30:59 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id A8B1CAC26; Mon, 23 Mar 2020 17:30:57 +0000 (UTC) Date: Mon, 23 Mar 2020 10:29:54 -0700 From: Davidlohr Bueso To: oneukum@suse.com Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Davidlohr Bueso Subject: Re: [PATCH 7/8] usb, cdc-acm: optimize barrier usage for Rmw atomic bitops Message-ID: <20200323172954.pyxw5v4pmuvkbjrp@linux-p48b> References: <20200129181545.25302-1-dave@stgolabs.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <20200129181545.25302-1-dave@stgolabs.net> User-Agent: NeoMutt/20180716 Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org ping? Can these please be picked up? On Wed, 29 Jan 2020, Davidlohr Bueso wrote: >We can avoid the unnecessary barrier on non LL/SC architectures, >such as x86. Instead, use the smp_mb__after_atomic() call. > >Signed-off-by: Davidlohr Bueso >--- > drivers/usb/class/cdc-acm.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > >diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c >index 62f4fb9b362f..0bc4b558f387 100644 >--- a/drivers/usb/class/cdc-acm.c >+++ b/drivers/usb/class/cdc-acm.c >@@ -842,7 +842,7 @@ static void acm_tty_unthrottle(struct tty_struct *tty) > clear_bit(ACM_THROTTLED, &acm->flags); > > /* Matches the smp_mb__after_atomic() in acm_read_bulk_callback(). */ >- smp_mb(); >+ smp_mb__after_atomic(); > > acm_submit_read_urbs(acm, GFP_KERNEL); > } >-- >2.16.4 >