[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>

diff --git a/drivers/staging/lirc/lirc_zilog.c b/drivers/staging/lirc/lirc_zilog.c
index 695c3df..a62b94b 100644 (file)
--- 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;