Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936337Ab3DHPQv (ORCPT ); Mon, 8 Apr 2013 11:16:51 -0400 Received: from mail.active-venture.com ([67.228.131.205]:50588 "EHLO mail.active-venture.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761819Ab3DHPQu (ORCPT ); Mon, 8 Apr 2013 11:16:50 -0400 X-Originating-IP: 108.223.40.66 Date: Mon, 8 Apr 2013 08:16:55 -0700 From: Guenter Roeck To: Hector Palacios Cc: linux-watchdog@vger.kernel.org, linux-kernel@vger.kernel.org, wim@iguana.be Subject: Re: [PATCH v3] watchdog: core: don't try to stop device if not running Message-ID: <20130408151655.GB20919@roeck-us.net> References: <1365433592-25687-1-git-send-email-hector.palacios@digi.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1365433592-25687-1-git-send-email-hector.palacios@digi.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2404 Lines: 62 On Mon, Apr 08, 2013 at 05:06:32PM +0200, Hector Palacios wrote: > A watchdog device may be stopped from userspace using WDIOC_SETOPTIONS > ioctl and flag WDIOS_DISABLECARD. If the device is closed after this > operation, watchdog_release() is called and status bits checked for > stopping it. Besides, if the device has not been unregistered a critical > message "watchdog did not stop!" is printed, although the ioctl may have > successfully stopped it already. > > Without the patch a user application sample code like this will successfully > stop the watchdog, but the kernel will output the message > "watchdog did not stop!": > > wd_fd = open("/dev/watchdog", O_RDWR); > > flags = WDIOS_DISABLECARD; > ioctl(wd_fd, WDIOC_SETOPTIONS, &flags); > > close(wd_fd); > > Signed-off-by: Hector Palacios Reviewed-by: Guenter Roeck > --- > > Changes from v1: > - Make it less intrusive with 'if/else if' clauses. > - Change the logic of 'err' variable for better readability of code. > - Remove one-liner if brackets that broke coding sytle. > Changes from v2: > - Revert "Change the logic of 'err'..." from v1 because otherwise the > 'else if' can't be reached if the watchdog is running. > > drivers/watchdog/watchdog_dev.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c > index ef8edec..6117c48 100644 > --- a/drivers/watchdog/watchdog_dev.c > +++ b/drivers/watchdog/watchdog_dev.c > @@ -470,8 +470,10 @@ static int watchdog_release(struct inode *inode, struct file *file) > * or if WDIOF_MAGICCLOSE is not set. If nowayout was set then > * watchdog_stop will fail. > */ > - if (test_and_clear_bit(WDOG_ALLOW_RELEASE, &wdd->status) || > - !(wdd->info->options & WDIOF_MAGICCLOSE)) > + if (!test_bit(WDOG_ACTIVE, &wdd->status)) > + err = 0; > + else if (test_and_clear_bit(WDOG_ALLOW_RELEASE, &wdd->status) || > + !(wdd->info->options & WDIOF_MAGICCLOSE)) > err = watchdog_stop(wdd); > > /* If the watchdog was not stopped, send a keepalive ping */ > -- > 1.8.2 > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/