From a30648550f2f758c9c00c493c8919f89f65438c4 Mon Sep 17 00:00:00 2001 From: Andy Walls Date: Wed, 26 Jan 2011 22:04:24 -0300 Subject: [PATCH] [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 Signed-off-by: Jarod Wilson Signed-off-by: Mauro Carvalho Chehab --- drivers/staging/lirc/lirc_zilog.c | 15 +++++---------- 1 file changed, 5 insertions(+), 10 deletions(-) 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 IR { 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 @@ static int lirc_thread(void *arg) 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 @@ static int open(struct inode *node, struct file *filep) 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 @@ static int close(struct inode *node, struct file *filep) 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 @@ static int ir_probe(struct i2c_client *client, const struct i2c_device_id *id) 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)); -- 2.7.4