W1: w1_process, block or sleep
The w1_process thread's sleeping and termination has been modified.
msleep_interruptible was replaced by schedule_timeout and schedule to
allow for kthread_stop and wake_up_process to interrupt the sleep and the
unbounded sleeping when a bus search is disabled. The W1_MASTER_NEED_EXIT
and flags variable were removed as they were redundant with
kthread_should_stop and kthread_stop. If w1_process is sleeping,
requesting a search will immediately wake it up rather than waiting for
the end of msleep_interruptible previously.
Signed-off-by: David Fries <david@fries.net>
Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c
index 730faa4..9b5c117 100644
--- a/drivers/w1/w1.c
+++ b/drivers/w1/w1.c
@@ -251,6 +251,7 @@
mutex_lock(&md->mutex);
md->search_count = simple_strtol(buf, NULL, 0);
mutex_unlock(&md->mutex);
+ wake_up_process(md->thread);
return count;
}
@@ -773,7 +774,7 @@
tmp64 = (triplet_ret >> 2);
rn |= (tmp64 << i);
- if (test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) {
+ if (kthread_should_stop()) {
printk(KERN_INFO "Abort w1_search (exiting)\n");
return;
}
@@ -811,8 +812,12 @@
int w1_process(void *data)
{
struct w1_master *dev = (struct w1_master *) data;
+ /* As long as w1_timeout is only set by a module parameter the sleep
+ * time can be calculated in jiffies once.
+ */
+ const unsigned long jtime = msecs_to_jiffies(w1_timeout * 1000);
- while (!kthread_should_stop() && !test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) {
+ while (!kthread_should_stop()) {
if (dev->search_count) {
mutex_lock(&dev->mutex);
w1_search_process(dev, W1_SEARCH);
@@ -820,7 +825,16 @@
}
try_to_freeze();
- msleep_interruptible(w1_timeout * 1000);
+ __set_current_state(TASK_INTERRUPTIBLE);
+
+ if (kthread_should_stop())
+ break;
+
+ /* Only sleep when the search is active. */
+ if (dev->search_count)
+ schedule_timeout(jtime);
+ else
+ schedule();
}
atomic_dec(&dev->refcnt);