From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755394AbaI3HmQ (ORCPT ); Tue, 30 Sep 2014 03:42:16 -0400 Received: from relay1.mentorg.com ([192.94.38.131]:56230 "EHLO relay1.mentorg.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751056AbaI3HmP (ORCPT ); Tue, 30 Sep 2014 03:42:15 -0400 From: "Sharma, Sanjeev" To: Julian Calaby CC: Johannes Berg , "dsd@gentoo.org" , "kune@deine-taler.de" , "linux-wireless@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "netdev@vger.kernel.org" Subject: RE: [PATCH v2] zd1211rw: replace ZD_ASSERT with lockdep_assert_held() Thread-Topic: [PATCH v2] zd1211rw: replace ZD_ASSERT with lockdep_assert_held() Thread-Index: AQHPzaji67ru1uysWEKojhy3lQjAn5v7vMNQgAXsTACAF73wAA== Date: Tue, 30 Sep 2014 07:42:11 +0000 Message-ID: References: <1410418407.1825.0.camel@jlt4.sipsolutions.net> <1410430179-19944-1-git-send-email-sanjeev_sharma@mentor.com> <1410430345.22863.0.camel@jlt4.sipsolutions.net> In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [137.202.0.76] Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id s8U7gM9s020036 -----Original Message----- From: Julian Calaby [mailto:julian.calaby@gmail.com] Sent: Monday, September 15, 2014 11:32 AM To: Sharma, Sanjeev Cc: Johannes Berg; dsd@gentoo.org; kune@deine-taler.de; linux-wireless@vger.kernel.org; linux-kernel@vger.kernel.org; netdev@vger.kernel.org Subject: Re: [PATCH v2] zd1211rw: replace ZD_ASSERT with lockdep_assert_held() Hi Sanjeev, On Thu, Sep 11, 2014 at 8:36 PM, Sharma, Sanjeev wrote: > -----Original Message----- > From: Johannes Berg [mailto:johannes@sipsolutions.net] > Sent: Thursday, September 11, 2014 3:42 PM > To: Sharma, Sanjeev > Cc: dsd@gentoo.org; kune@deine-taler.de; > linux-wireless@vger.kernel.org; linux-kernel@vger.kernel.org; > netdev@vger.kernel.org > Subject: Re: [PATCH v2] zd1211rw: replace ZD_ASSERT with > lockdep_assert_held() > > On Thu, 2014-09-11 at 15:39 +0530, Sanjeev Sharma wrote: >> on some architecture spin_is_locked() always return false in >> uniprocessor configuration and therefore it would be advise to >> replace with lockdep_assert_held(). >> >> Signed-off-by: Sanjeev Sharma >> --- >> Changes in v2: >> - corrected the typo > >> Now it compiles, but you got the logic wrong. > >> +++ b/drivers/net/wireless/zd1211rw/zd_mac.c >> @@ -235,7 +235,7 @@ void zd_mac_clear(struct zd_mac *mac) { >> flush_workqueue(zd_workqueue); >> zd_chip_clear(&mac->chip); >> - ZD_ASSERT(!spin_is_locked(&mac->lock)); >> + lockdep_assert_held(&mac->lock); >> ZD_MEMCLEAR(mac, sizeof(struct zd_mac)); } > >>Look closely at this again. > > I didn't understand where I put wrong logic ? I find it helps to spell out what code is doing in words. E.g. the line you're removing is: ZD_ASSERT(!spin_is_locked(&mac->lock)); So, we'll assert when spin_is_locked(&mac->lock) is false, i.e. when mac->lock is not spin locked. This isn't the same as what you're replacing it with. I feel logic is absolutely correct and if you expand it will looks like .. +#define lockdep_assert_held(l) do { \ + WARN_ON(debug_locks && !lockdep_is_held(l)); \ + } while (0) Please refer http://lkml.iu.edu/hypermail/linux/kernel/1203.2/00369.html and also see include/linux/lockdep.h for more detail. Thanks Sanjeev Sharma {.n++%ݶw{.n+{G{ayʇڙ,jfhz_(階ݢj"mG?&~iOzv^m ?I