Return-path: Received: from bu3sch.de ([62.75.166.246]:56802 "EHLO vs166246.vserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754341AbYG3N1y (ORCPT ); Wed, 30 Jul 2008 09:27:54 -0400 From: Michael Buesch To: Larry Finger Subject: Re: [RFC/RFT] rtl8187: Protect the config callback from mac80211 with a mutex Date: Wed, 30 Jul 2008 15:27:26 +0200 Cc: Hin-Tak Leung , herton Ronaldo Krzesinski , Pavel Roskin , wireless References: <48900654.7030100@lwfinger.net> <200807301524.40411.mb@bu3sch.de> In-Reply-To: <200807301524.40411.mb@bu3sch.de> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Message-Id: <200807301527.26432.mb@bu3sch.de> (sfid-20080730_152757_774951_930A5D6B) Sender: linux-wireless-owner@vger.kernel.org List-ID: On Wednesday 30 July 2008 15:24:40 Michael Buesch wrote: > On Wednesday 30 July 2008 08:12:36 Larry Finger wrote: > > Herton, > > > > Does this patch help your problem? I haven't done much testing, but things seem > > to be better with it here. > > > > Larry > > > > ================== > > > > Some users of the RTL8187B have experienced difficulties since commit > > 8f87dd7e540d455f8e7f11478133b85edc969c67 that introduced the power > > management wext hooks. This difficulty has not made much sense until > > it was realized that it was possible for mac80211 to make a call to the > > config routine while that routine was already being executed. This patch > > protects the critical section with a mutex. > > > > Signed-off-by: Larry Finger > > --- > > > > Index: wireless-testing/drivers/net/wireless/rtl8187.h > > =================================================================== > > --- wireless-testing.orig/drivers/net/wireless/rtl8187.h > > +++ wireless-testing/drivers/net/wireless/rtl8187.h > > @@ -94,6 +94,7 @@ struct rtl8187_priv { > > const struct rtl818x_rf_ops *rf; > > struct ieee80211_vif *vif; > > int mode; > > + struct mutex mutex; /* used to lock config callback */ > > Well, hm. > Using locks to protect code is a bad idea, most of the time. > So that comment makes no sense. > > What that lock _probably_ does it to protect the configuration > data in struct rtl8187_priv. So you'd better find out which data > that is and clarify the comment. and the mutex name, of course. /* Mutex to protect the device configuration data, * which is foobar and bizzbaz */ struct mutex conf_mutex; -- Greetings Michael.