[media] lirc_zilog: Remove unneeded rx->buf_lock

Remove the rx->buf_lock that protected the rx->buf lirc_buffer.  The
underlying operations on the objects within the lirc_buffer are already
protected by spinlocks, or the objects are constant (e.g. chunk_size).

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>

1 files changed, 9 insertions, 14 deletions

diff --git a/drivers/staging/lirc/lirc_zilog.c b/drivers/staging/lirc/lirc_zilog.c
index 695c3df93ca8..a62b94bf6a1a 100644
--- a/drivers/staging/lirc/lirc_zilog.c
+++ b/drivers/staging/lirc/lirc_zilog.c
@@ -67,9 +67,8 @@ struct IR_rx {
         /* RX device */
         struct i2c_client *c;
 
-        /* RX device buffer & lock */
+        /* RX device buffer */
         struct lirc_buffer buf;
-        struct mutex buf_lock;
 
         /* RX polling thread data */
         struct task_struct *task;
@@ -718,18 +717,15 @@ static ssize_t read(struct file *filep, char *outbuf, size_t n, loff_t *ppos)
         struct IR *ir = filep->private_data;
         struct IR_rx *rx = ir->rx;
         int ret = 0, written = 0;
+        unsigned int m;
         DECLARE_WAITQUEUE(wait, current);
 
         dprintk("read called\n");
         if (rx == NULL)
                 return -ENODEV;
 
-        if (mutex_lock_interruptible(&rx->buf_lock))
-                return -ERESTARTSYS;
-
         if (n % rx->buf.chunk_size) {
                 dprintk("read result = -EINVAL\n");
-                mutex_unlock(&rx->buf_lock);
                 return -EINVAL;
         }
 
@@ -767,19 +763,19 @@ static ssize_t read(struct file *filep, char *outbuf, size_t n, loff_t *ppos)
                         set_current_state(TASK_INTERRUPTIBLE);
                 } else {
                         unsigned char buf[rx->buf.chunk_size];
-                        lirc_buffer_read(&rx->buf, buf);
-                        ret = copy_to_user((void *)outbuf+written, buf,
-                                           rx->buf.chunk_size);
-                        written += rx->buf.chunk_size;
+                        m = lirc_buffer_read(&rx->buf, buf);
+                        if (m == rx->buf.chunk_size) {
+                                ret = copy_to_user((void *)outbuf+written, buf,
+                                                   rx->buf.chunk_size);
+                                written += rx->buf.chunk_size;
+                        }
                 }
         }
 
         remove_wait_queue(&rx->buf.wait_poll, &wait);
         set_current_state(TASK_RUNNING);
-        mutex_unlock(&rx->buf_lock);
 
-        dprintk("read result = %s (%d)\n",
-                ret ? "-EFAULT" : "OK", ret);
+        dprintk("read result = %d (%s)\n", ret, ret ? "Error" : "OK");
 
         return ret ? ret : written;
 }
@@ -1327,7 +1323,6 @@ static int ir_probe(struct i2c_client *client, const struct i2c_device_id *id)
                 if (ret)
                         goto out_free_xx;
 
-                mutex_init(&ir->rx->buf_lock);
                 ir->rx->c = client;
                 ir->rx->hdpvr_data_fmt =
                                (id->driver_data & ID_FLAG_HDPVR) ? true : false;