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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 6F932C4332B for ; Wed, 18 Mar 2020 20:48:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5004C20775 for ; Wed, 18 Mar 2020 20:48:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727395AbgCRUsS (ORCPT ); Wed, 18 Mar 2020 16:48:18 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:58410 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726631AbgCRUr3 (ORCPT ); Wed, 18 Mar 2020 16:47:29 -0400 Received: from p5de0bf0b.dip0.t-ipconnect.de ([93.224.191.11] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1jEfaH-00065m-Ie; Wed, 18 Mar 2020 21:46:37 +0100 Received: from nanos.tec.linutronix.de (localhost [IPv6:::1]) by nanos.tec.linutronix.de (Postfix) with ESMTP id B08301040C7; Wed, 18 Mar 2020 21:46:35 +0100 (CET) Message-Id: <20200318204407.700914073@linutronix.de> User-Agent: quilt/0.65 Date: Wed, 18 Mar 2020 21:43:05 +0100 From: Thomas Gleixner To: LKML Cc: Peter Zijlstra , Linus Torvalds , Ingo Molnar , Will Deacon , "Paul E . McKenney" , Joel Fernandes , Steven Rostedt , Randy Dunlap , Sebastian Andrzej Siewior , Felipe Balbi , Greg Kroah-Hartman , linux-usb@vger.kernel.org, Logan Gunthorpe , Kurt Schwemmer , Bjorn Helgaas , linux-pci@vger.kernel.org, Kalle Valo , "David S. Miller" , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, Oleg Nesterov , Davidlohr Bueso , Michael Ellerman , Arnd Bergmann , linuxppc-dev@lists.ozlabs.org Subject: [patch V2 03/15] usb: gadget: Use completion interface instead of open coding it References: <20200318204302.693307984@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org ep_io() uses a completion on stack and open codes the waiting with: wait_event_interruptible (done.wait, done.done); and wait_event (done.wait, done.done); This waits in non-exclusive mode for complete(), but there is no reason to do so because the completion can only be waited for by the task itself and complete() wakes exactly one exlusive waiter. Replace the open coded implementation with the corresponding wait_for_completion*() functions. No functional change. Reported-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Cc: Felipe Balbi Cc: Greg Kroah-Hartman Cc: linux-usb@vger.kernel.org --- V2: New patch to avoid the conversion to swait interfaces later --- drivers/usb/gadget/legacy/inode.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/usb/gadget/legacy/inode.c +++ b/drivers/usb/gadget/legacy/inode.c @@ -344,7 +344,7 @@ ep_io (struct ep_data *epdata, void *buf spin_unlock_irq (&epdata->dev->lock); if (likely (value == 0)) { - value = wait_event_interruptible (done.wait, done.done); + value = wait_for_completion_interruptible(&done); if (value != 0) { spin_lock_irq (&epdata->dev->lock); if (likely (epdata->ep != NULL)) { @@ -353,7 +353,7 @@ ep_io (struct ep_data *epdata, void *buf usb_ep_dequeue (epdata->ep, epdata->req); spin_unlock_irq (&epdata->dev->lock); - wait_event (done.wait, done.done); + wait_for_completion(&done); if (epdata->status == -ECONNRESET) epdata->status = -EINTR; } else { 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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 0894EC4332B for ; Wed, 18 Mar 2020 21:12:54 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B316120409 for ; Wed, 18 Mar 2020 21:12:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B316120409 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linutronix.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 48jN6W39nMzDr2k for ; Thu, 19 Mar 2020 08:12:51 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=linutronix.de (client-ip=2a0a:51c0:0:12e:550::1; helo=galois.linutronix.de; envelope-from=tglx@linutronix.de; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=linutronix.de Received: from Galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) (using TLSv1.2 with cipher DHE-RSA-AES256-SHA256 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 48jMXp5cQdzDqxB for ; Thu, 19 Mar 2020 07:47:06 +1100 (AEDT) Received: from p5de0bf0b.dip0.t-ipconnect.de ([93.224.191.11] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1jEfaH-00065m-Ie; Wed, 18 Mar 2020 21:46:37 +0100 Received: from nanos.tec.linutronix.de (localhost [IPv6:::1]) by nanos.tec.linutronix.de (Postfix) with ESMTP id B08301040C7; Wed, 18 Mar 2020 21:46:35 +0100 (CET) Message-Id: <20200318204407.700914073@linutronix.de> User-Agent: quilt/0.65 Date: Wed, 18 Mar 2020 21:43:05 +0100 From: Thomas Gleixner To: LKML Subject: [patch V2 03/15] usb: gadget: Use completion interface instead of open coding it References: <20200318204302.693307984@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1, SHORTCIRCUIT=-0.0001 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Randy Dunlap , Greg Kroah-Hartman , Peter Zijlstra , linux-pci@vger.kernel.org, Sebastian Andrzej Siewior , Joel Fernandes , Will Deacon , Ingo Molnar , Davidlohr Bueso , Arnd Bergmann , "Paul E . McKenney" , linuxppc-dev@lists.ozlabs.org, Steven Rostedt , Bjorn Helgaas , Kurt Schwemmer , Kalle Valo , Felipe Balbi , Logan Gunthorpe , linux-usb@vger.kernel.org, linux-wireless@vger.kernel.org, Oleg Nesterov , netdev@vger.kernel.org, Linus Torvalds , "David S. Miller" Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" ep_io() uses a completion on stack and open codes the waiting with: wait_event_interruptible (done.wait, done.done); and wait_event (done.wait, done.done); This waits in non-exclusive mode for complete(), but there is no reason to do so because the completion can only be waited for by the task itself and complete() wakes exactly one exlusive waiter. Replace the open coded implementation with the corresponding wait_for_completion*() functions. No functional change. Reported-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Cc: Felipe Balbi Cc: Greg Kroah-Hartman Cc: linux-usb@vger.kernel.org --- V2: New patch to avoid the conversion to swait interfaces later --- drivers/usb/gadget/legacy/inode.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/usb/gadget/legacy/inode.c +++ b/drivers/usb/gadget/legacy/inode.c @@ -344,7 +344,7 @@ ep_io (struct ep_data *epdata, void *buf spin_unlock_irq (&epdata->dev->lock); if (likely (value == 0)) { - value = wait_event_interruptible (done.wait, done.done); + value = wait_for_completion_interruptible(&done); if (value != 0) { spin_lock_irq (&epdata->dev->lock); if (likely (epdata->ep != NULL)) { @@ -353,7 +353,7 @@ ep_io (struct ep_data *epdata, void *buf usb_ep_dequeue (epdata->ep, epdata->req); spin_unlock_irq (&epdata->dev->lock); - wait_event (done.wait, done.done); + wait_for_completion(&done); if (epdata->status == -ECONNRESET) epdata->status = -EINTR; } else {