From patchwork Sun Jun 24 22:08:34 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sebastian Andrzej Siewior X-Patchwork-Id: 10484887 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 4E03F603B5 for ; Sun, 24 Jun 2018 22:09:08 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4239A28849 for ; Sun, 24 Jun 2018 22:09:08 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3663628857; Sun, 24 Jun 2018 22:09:08 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C8D9B28849 for ; Sun, 24 Jun 2018 22:09:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752087AbeFXWJE (ORCPT ); Sun, 24 Jun 2018 18:09:04 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:45331 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751979AbeFXWJD (ORCPT ); Sun, 24 Jun 2018 18:09:03 -0400 Received: from localhost ([127.0.0.1] helo=bazinga.breakpoint.cc) by Galois.linutronix.de with esmtp (Exim 4.80) (envelope-from ) id 1fXDBl-0000Vg-OC; Mon, 25 Jun 2018 00:08:54 +0200 From: Sebastian Andrzej Siewior To: linux-usb@vger.kernel.org Cc: tglx@linutronix.de, Greg Kroah-Hartman , Sebastian Andrzej Siewior , Oliver Neukum Subject: [PATCH 01/12] usb: cdc-acm: use irqsave() in USB's complete callback Date: Mon, 25 Jun 2018 00:08:34 +0200 Message-Id: <20180624220845.6726-2-bigeasy@linutronix.de> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180624220845.6726-1-bigeasy@linutronix.de> References: <20180624220845.6726-1-bigeasy@linutronix.de> MIME-Version: 1.0 Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The USB completion callback does not disable interrupts while acquiring the lock. We want to remove the local_irq_disable() invocation from __usb_hcd_giveback_urb() and therefore it is required for the callback handler to disable the interrupts while acquiring the lock. The callback may be invoked either in IRQ or BH context depending on the USB host controller. Use the _irqsave() variant of the locking primitives. Cc: Oliver Neukum Cc: Greg Kroah-Hartman Signed-off-by: Sebastian Andrzej Siewior --- drivers/usb/class/cdc-acm.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index 7b366a6c0b49..682557d6f339 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -276,6 +276,7 @@ static void acm_process_notification(struct acm *acm, unsigned char *buf) { int newctrl; int difference; + unsigned long flags; struct usb_cdc_notification *dr = (struct usb_cdc_notification *)buf; unsigned char *data = buf + sizeof(struct usb_cdc_notification); @@ -303,7 +304,7 @@ static void acm_process_notification(struct acm *acm, unsigned char *buf) } difference = acm->ctrlin ^ newctrl; - spin_lock(&acm->read_lock); + spin_lock_irqsave(&acm->read_lock, flags); acm->ctrlin = newctrl; acm->oldcount = acm->iocount; @@ -321,7 +322,7 @@ static void acm_process_notification(struct acm *acm, unsigned char *buf) acm->iocount.parity++; if (difference & ACM_CTRL_OVERRUN) acm->iocount.overrun++; - spin_unlock(&acm->read_lock); + spin_unlock_irqrestore(&acm->read_lock, flags); if (difference) wake_up_all(&acm->wioctl);