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path: root/drivers/w1/w1_int.c
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Diffstat (limited to 'drivers/w1/w1_int.c')
-rw-r--r--drivers/w1/w1_int.c32
1 files changed, 26 insertions, 6 deletions
diff --git a/drivers/w1/w1_int.c b/drivers/w1/w1_int.c
index 3fd6e6651fbe..a3a54567bfba 100644
--- a/drivers/w1/w1_int.c
+++ b/drivers/w1/w1_int.c
@@ -29,7 +29,6 @@
#include "w1_netlink.h"
#include "w1_int.h"
-static u32 w1_ids = 1;
static int w1_search_count = -1; /* Default is continual scan */
module_param_named(search_count, w1_search_count, int, 0);
@@ -102,9 +101,10 @@ static void w1_free_dev(struct w1_master *dev)
int w1_add_master_device(struct w1_bus_master *master)
{
- struct w1_master *dev;
+ struct w1_master *dev, *entry;
int retval = 0;
struct w1_netlink_msg msg;
+ int id, found;
/* validate minimum functionality */
if (!(master->touch_bit && master->reset_bus) &&
@@ -126,13 +126,33 @@ int w1_add_master_device(struct w1_bus_master *master)
master->set_pullup = NULL;
}
- dev = w1_alloc_dev(w1_ids++, w1_max_slave_count, w1_max_slave_ttl, &w1_master_driver, &w1_master_device);
- if (!dev)
+ /* Lock until the device is added (or not) to w1_masters. */
+ mutex_lock(&w1_mlock);
+ /* Search for the first available id (starting at 1). */
+ id = 0;
+ do {
+ ++id;
+ found = 0;
+ list_for_each_entry(entry, &w1_masters, w1_master_entry) {
+ if (entry->id == id) {
+ found = 1;
+ break;
+ }
+ }
+ } while (found);
+
+ dev = w1_alloc_dev(id, w1_max_slave_count, w1_max_slave_ttl,
+ &w1_master_driver, &w1_master_device);
+ if (!dev) {
+ mutex_unlock(&w1_mlock);
return -ENOMEM;
+ }
retval = w1_create_master_attributes(dev);
- if (retval)
+ if (retval) {
+ mutex_unlock(&w1_mlock);
goto err_out_free_dev;
+ }
memcpy(dev->bus_master, master, sizeof(struct w1_bus_master));
@@ -144,10 +164,10 @@ int w1_add_master_device(struct w1_bus_master *master)
dev_err(&dev->dev,
"Failed to create new kernel thread. err=%d\n",
retval);
+ mutex_unlock(&w1_mlock);
goto err_out_rm_attr;
}
- mutex_lock(&w1_mlock);
list_add(&dev->w1_master_entry, &w1_masters);
mutex_unlock(&w1_mlock);