2.6.26-stable review patch. If anyone has any objections, please let us know.
------------------
From: Larry Finger <Larry.Finger@lwfinger.net>
With the rtl8187 driver, the config routine is not protected against
access before a previous call has completed. When this happens, the
TX loopback that is needed to change channels may cause the chip to
be locked with a reset needed to restore communications. This patch
entered mainline as commit 7dcdd073bf78bb6958bbc12a1a47754a0f3c4721.
The problem was found by Herton Ronaldo Krzesinski <herton@mandriva.com.br>,
who also suggested this type of fix.
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Acked-by: Herton Ronaldo Krzesinski <herton@mandriva.com.br>
Acked-by: Hin-Tak Leung <htl10@users.sourceforge.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
drivers/net/wireless/rtl8187.h | 4 ++++
drivers/net/wireless/rtl8187_dev.c | 3 +++
2 files changed, 7 insertions(+)
--- a/drivers/net/wireless/rtl8187_dev.c
+++ b/drivers/net/wireless/rtl8187_dev.c
@@ -580,6 +580,7 @@ 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
@@ -610,6 +611,7 @@ 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;
}
@@ -814,6 +816,7 @@ 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, rtl8187 V%d + %s\n",
wiphy_name(dev->wiphy), print_mac(mac, dev->wiphy->perm_addr),
--- a/drivers/net/wireless/rtl8187.h
+++ b/drivers/net/wireless/rtl8187.h
@@ -67,6 +67,10 @@ 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];
--
--
