Return-path: Received: from perninha.conectiva.com.br ([200.140.247.100]:38456 "EHLO perninha.conectiva.com.br" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752062AbYG3SVF (ORCPT ); Wed, 30 Jul 2008 14:21:05 -0400 From: Herton Ronaldo Krzesinski To: Larry Finger Subject: Re: [PATCH] rtl8187: Fix lockups due to concurrent access to config routine Date: Wed, 30 Jul 2008 15:21:11 -0300 Cc: John Linville , "Hin-Tak Leung" , wireless References: <489091C6.9070805@lwfinger.net> In-Reply-To: <489091C6.9070805@lwfinger.net> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Message-Id: <200807301521.12233.herton@mandriva.com.br> (sfid-20080730_202109_775297_36A593A7) Sender: linux-wireless-owner@vger.kernel.org List-ID: Em Wednesday 30 July 2008 13:07:34 Larry Finger escreveu: > 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. > > The problem was found by Herton Ronaldo Krzesinski , > who also suggested this type of fix. > > Signed-off-by: Larry Finger > Acked-by: Herton Ronaldo Krzesinski > --- Hi, the patch has some extra/missing spaces that makes it not apply, but fixing manually it applies here. I thought at first it was not up-todate wireless testing here. > > John, > > This is 2.6.27 material as it fixes a bug. > > Larry > --- > > > 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 +94,10 @@ struct rtl8187_priv { > const struct rtl818x_rf_ops *rf; > struct ieee80211_vif *vif; > int mode; > + /* The mutex protects the TX loopback state. > + * Any attempt to set channels concurrently locks the device. > + */ > + struct mutex conf_mutex; > > /* rtl8187 specific */ > struct ieee80211_channel channels[14]; > Index: wireless-testing/drivers/net/wireless/rtl8187_dev.c > =================================================================== > --- wireless-testing.orig/drivers/net/wireless/rtl8187_dev.c > +++ wireless-testing/drivers/net/wireless/rtl8187_dev.c > @@ -864,6 +864,7 @@ static int rtl8187_config(struct ieee802 > struct rtl8187_priv *priv = dev->priv; > u32 reg; > > + mutex_lock(&priv->conf_mutex); > reg = rtl818x_ioread32(priv, &priv->map->TX_CONF); > /* Enable TX loopback on MAC level to avoid TX during channel > * changes, as this has be seen to causes problems and the > @@ -896,6 +897,7 @@ static int rtl8187_config(struct ieee802 > rtl818x_iowrite16(priv, &priv->map->ATIMTR_INTERVAL, 100); > rtl818x_iowrite16(priv, &priv->map->BEACON_INTERVAL, 100); > rtl818x_iowrite16(priv, &priv->map->BEACON_INTERVAL_TIME, 100); > + mutex_unlock(&priv->conf_mutex); > return 0; > } > > @@ -1187,6 +1189,7 @@ static int __devinit rtl8187_probe(struc > printk(KERN_ERR "rtl8187: Cannot register device\n"); > goto err_free_dev; > } > + mutex_init(&priv->conf_mutex); > > printk(KERN_INFO "%s: hwaddr %s, %s V%d + %s\n", > wiphy_name(dev->wiphy), print_mac(mac, dev->wiphy->perm_addr), > -- []'s Herton