[media] lirc_zilog: Convert the instance open count to an atomic_t
The open count is simply used for deciding if the Rx polling thread
needs to poll the IR chip for userspace. Simplify the manipulation
of the open count by using an atomic_t and not requiring a lock
The polling thread errantly didn't try to take the lock anyway.
Signed-off-by: Andy Walls <awalls@md.metrocast.net>
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/staging/lirc/lirc_zilog.c b/drivers/staging/lirc/lirc_zilog.c
index 39f7b53..c857b99 100644
--- a/drivers/staging/lirc/lirc_zilog.c
+++ b/drivers/staging/lirc/lirc_zilog.c
@@ -94,7 +94,7 @@
struct lirc_driver l;
struct mutex ir_lock;
- int open;
+ atomic_t open_count;
struct i2c_adapter *adapter;
struct IR_rx *rx;
@@ -279,7 +279,7 @@
set_current_state(TASK_INTERRUPTIBLE);
/* if device not opened, we can sleep half a second */
- if (!ir->open) {
+ if (atomic_read(&ir->open_count) == 0) {
schedule_timeout(HZ/2);
continue;
}
@@ -1094,10 +1094,7 @@
if (ir == NULL)
return -ENODEV;
- /* increment in use count */
- mutex_lock(&ir->ir_lock);
- ++ir->open;
- mutex_unlock(&ir->ir_lock);
+ atomic_inc(&ir->open_count);
/* stash our IR struct */
filep->private_data = ir;
@@ -1115,10 +1112,7 @@
return -ENODEV;
}
- /* decrement in use count */
- mutex_lock(&ir->ir_lock);
- --ir->open;
- mutex_unlock(&ir->ir_lock);
+ atomic_dec(&ir->open_count);
return 0;
}
@@ -1294,6 +1288,7 @@
ir->adapter = adap;
mutex_init(&ir->ir_lock);
+ atomic_set(&ir->open_count, 0);
/* set lirc_dev stuff */
memcpy(&ir->l, &lirc_template, sizeof(struct lirc_driver));