[PATCH 4/30] W1: w1_process, block or sleep

Evgeniy Polyakov
2008-07-11T13:48:46Z

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>

---
drivers/w1/w1.c | 20 +++++++++++++++++---
drivers/w1/w1.h | 4 ----
drivers/w1/w1_int.c | 2 --
3 files changed, 17 insertions(+), 9 deletions(-)

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 @@ static ssize_t w1_master_attribute_store_search(struct device * dev,
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 @@ void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb
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 @@ void w1_search_process(struct w1_master *dev, u8 search_type)
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 @@ int w1_process(void *data)
}

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);
diff --git a/drivers/w1/w1.h b/drivers/w1/w1.h
index 13e0ea8..34ee01e 100644
--- a/drivers/w1/w1.h
+++ b/drivers/w1/w1.h
@@ -149,8 +149,6 @@ struct w1_bus_master
u8, w1_slave_found_callback);
};

-#define W1_MASTER_NEED_EXIT 0
-
struct w1_master
{
struct list_head w1_master_entry;
@@ -169,8 +167,6 @@ struct w1_master
void *priv;
int priv_size;

- long flags;
-
struct task_struct *thread;
struct mutex mutex;

diff --git a/drivers/w1/w1_int.c b/drivers/w1/w1_int.c
index 36ff402..bd877b2 100644
--- a/drivers/w1/w1_int.c
+++ b/drivers/w1/w1_int.c
@@ -142,7 +142,6 @@ int w1_add_master_device(struct w1_bus_master *master)

#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:
@@ -158,7 +157,6 @@ void __w1_remove_master_device(struct w1_master *dev)
struct w1_netlink_msg msg;
struct w1_slave *sl, *sln;

- set_bit(W1_MASTER_NEED_EXIT, &dev->flags);
kthread_stop(dev->thread);

mutex_lock(&w1_mlock);
--
1.4.4.4