From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754368AbaHKSTM (ORCPT ); Mon, 11 Aug 2014 14:19:12 -0400 Received: from mail-pd0-f170.google.com ([209.85.192.170]:43060 "EHLO mail-pd0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751444AbaHKSTJ (ORCPT ); Mon, 11 Aug 2014 14:19:09 -0400 Date: Mon, 11 Aug 2014 11:19:05 -0700 From: Guenter Roeck To: Sanjeev Sharma Cc: gregkh@linuxfoundation.org, hdegoede@redhat.com, kraxel@redhat.com, mdharm-usb@one-eyed-alien.net, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org Subject: Re: [PATCH] uas: replace WARN_ON_ONCE() with assert_spin_locked(). Message-ID: <20140811181905.GA25727@roeck-us.net> References: <1407743966-25325-1-git-send-email-sanjeev_sharma@mentor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1407743966-25325-1-git-send-email-sanjeev_sharma@mentor.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 On Mon, Aug 11, 2014 at 01:29:26PM +0530, Sanjeev Sharma wrote: > spin_is_locked() always return false in uniprocessor configuration and therefore it > would be advise to repalce with assert_spin_locked(). > > Signed-off-by: Sanjeev Sharma > --- > drivers/usb/storage/uas.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/drivers/usb/storage/uas.c b/drivers/usb/storage/uas.c > index 3f42785..8e5877d 100644 > --- a/drivers/usb/storage/uas.c > +++ b/drivers/usb/storage/uas.c > @@ -154,7 +154,7 @@ static void uas_mark_cmd_dead(struct uas_dev_info *devinfo, > struct scsi_cmnd *cmnd = container_of(scp, struct scsi_cmnd, SCp); > > uas_log_cmd_state(cmnd, caller); > - WARN_ON_ONCE(!spin_is_locked(&devinfo->lock)); > + assert_spin_locked(&devinfo->lock); Seems to me that replacing WARN_ON_ONCE (which may be annoying but only creates a traceback, and only once) with assert_spin_locked (which crashes the kernel) is a bit drastic. Guenter