diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/w1/w1_int.c | 32 |
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); |