Commit 01e14d6d authored by David Fries's avatar David Fries Committed by Linus Torvalds
Browse files

W1: don't delay search start



Move the creation of the w1_process thread to after the device has been
initialized.  This way w1_process doesn't have to check to see if it has
been initialized and the bus search can proceed without sleeping.  That
also eliminates two checks in the w1_process loop.  The sleep now happens
at the end of the loop not the beginning.

Also added a comment for why the atomic_set was 2.
Signed-off-by: default avatarDavid Fries <david@fries.net>
Signed-off-by: default avatarEvgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 0d671b27
......@@ -813,21 +813,14 @@ int w1_process(void *data)
struct w1_master *dev = (struct w1_master *) data;
while (!kthread_should_stop() && !test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) {
if (dev->search_count) {
mutex_lock(&dev->mutex);
w1_search_process(dev, W1_SEARCH);
mutex_unlock(&dev->mutex);
}
try_to_freeze();
msleep_interruptible(w1_timeout * 1000);
if (kthread_should_stop() || test_bit(W1_MASTER_NEED_EXIT, &dev->flags))
break;
if (!dev->initialized)
continue;
if (dev->search_count == 0)
continue;
mutex_lock(&dev->mutex);
w1_search_process(dev, W1_SEARCH);
mutex_unlock(&dev->mutex);
}
atomic_dec(&dev->refcnt);
......
......@@ -61,6 +61,9 @@ static struct w1_master * w1_alloc_dev(u32 id, int slave_count, int slave_ttl,
dev->slave_ttl = slave_ttl;
dev->search_count = -1; /* continual scan */
/* 1 for w1_process to decrement
* 1 for __w1_remove_master_device to decrement
*/
atomic_set(&dev->refcnt, 2);
INIT_LIST_HEAD(&dev->slist);
......@@ -109,23 +112,23 @@ int w1_add_master_device(struct w1_bus_master *master)
if (!dev)
return -ENOMEM;
retval = w1_create_master_attributes(dev);
if (retval)
goto err_out_free_dev;
memcpy(dev->bus_master, master, sizeof(struct w1_bus_master));
dev->initialized = 1;
dev->thread = kthread_run(&w1_process, dev, "%s", dev->name);
if (IS_ERR(dev->thread)) {
retval = PTR_ERR(dev->thread);
dev_err(&dev->dev,
"Failed to create new kernel thread. err=%d\n",
retval);
goto err_out_free_dev;
goto err_out_rm_attr;
}
retval = w1_create_master_attributes(dev);
if (retval)
goto err_out_kill_thread;
memcpy(dev->bus_master, master, sizeof(struct w1_bus_master));
dev->initialized = 1;
mutex_lock(&w1_mlock);
list_add(&dev->w1_master_entry, &w1_masters);
mutex_unlock(&w1_mlock);
......@@ -137,8 +140,13 @@ int w1_add_master_device(struct w1_bus_master *master)
return 0;
#if 0 /* Thread cleanup code, not required currently. */
err_out_kill_thread:
set_bit(W1_MASTER_NEED_EXIT, &dev->flags);
kthread_stop(dev->thread);
#endif
err_out_rm_attr:
w1_destroy_master_attributes(dev);
err_out_free_dev:
w1_free_dev(dev);
......
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