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authorJean Delvare <khali@linux-fr.org>2011-05-01 18:18:49 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2011-05-09 15:06:37 -0700
commitbcd0df39767d1c4352566d909291deac099b222b (patch)
treec0245c316ef9161f9aab916fae2ae7ee70ed5ef8 /drivers
parentbbb267c7d49c3a9be39e7f59bae56500afee0ab3 (diff)
downloadlinux-linaro-android-bcd0df39767d1c4352566d909291deac099b222b.tar.gz
i2c-parport: Fix adapter list handling
commit 56acc7a39ac4ac7638cdc32cd3d0832ebbc834e4 upstream. Use a standard list with proper locking to handle the list of adapters. Thankfully it only matters on systems with more than one parallel port, which are very rare. Thanks to Lukasz Kapiec for reporting the problem to me. Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/i2c/busses/i2c-parport.c27
1 files changed, 14 insertions, 13 deletions
diff --git a/drivers/i2c/busses/i2c-parport.c b/drivers/i2c/busses/i2c-parport.c
index 0eb1515541e..2dbba163b10 100644
--- a/drivers/i2c/busses/i2c-parport.c
+++ b/drivers/i2c/busses/i2c-parport.c
@@ -1,7 +1,7 @@
/* ------------------------------------------------------------------------ *
* i2c-parport.c I2C bus over parallel port *
* ------------------------------------------------------------------------ *
- Copyright (C) 2003-2010 Jean Delvare <khali@linux-fr.org>
+ Copyright (C) 2003-2011 Jean Delvare <khali@linux-fr.org>
Based on older i2c-philips-par.c driver
Copyright (C) 1995-2000 Simon G. Vogl
@@ -33,6 +33,8 @@
#include <linux/i2c-algo-bit.h>
#include <linux/i2c-smbus.h>
#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
#include "i2c-parport.h"
/* ----- Device list ------------------------------------------------------ */
@@ -43,10 +45,11 @@ struct i2c_par {
struct i2c_algo_bit_data algo_data;
struct i2c_smbus_alert_setup alert_data;
struct i2c_client *ara;
- struct i2c_par *next;
+ struct list_head node;
};
-static struct i2c_par *adapter_list;
+static LIST_HEAD(adapter_list);
+static DEFINE_MUTEX(adapter_list_lock);
/* ----- Low-level parallel port access ----------------------------------- */
@@ -228,8 +231,9 @@ static void i2c_parport_attach (struct parport *port)
}
/* Add the new adapter to the list */
- adapter->next = adapter_list;
- adapter_list = adapter;
+ mutex_lock(&adapter_list_lock);
+ list_add_tail(&adapter->node, &adapter_list);
+ mutex_unlock(&adapter_list_lock);
return;
ERROR1:
@@ -241,11 +245,11 @@ ERROR0:
static void i2c_parport_detach (struct parport *port)
{
- struct i2c_par *adapter, *prev;
+ struct i2c_par *adapter, *_n;
/* Walk the list */
- for (prev = NULL, adapter = adapter_list; adapter;
- prev = adapter, adapter = adapter->next) {
+ mutex_lock(&adapter_list_lock);
+ list_for_each_entry_safe(adapter, _n, &adapter_list, node) {
if (adapter->pdev->port == port) {
if (adapter->ara) {
parport_disable_irq(port);
@@ -259,14 +263,11 @@ static void i2c_parport_detach (struct parport *port)
parport_release(adapter->pdev);
parport_unregister_device(adapter->pdev);
- if (prev)
- prev->next = adapter->next;
- else
- adapter_list = adapter->next;
+ list_del(&adapter->node);
kfree(adapter);
- return;
}
}
+ mutex_unlock(&adapter_list_lock);
}
static struct parport_driver i2c_parport_driver = {