staging: comedi: comedi_fops: remove the goto's in comedi_read()

Use comedi_dev_from_minor() to simplify the return -ENODEV tests.

Cleanup the sanity checking a bit and remove the need for the goto's
when returning an initial error condition.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c
index 093f403..cf1410d 100644 (file)
--- a/drivers/staging/comedi/comedi_fops.c
+++ b/drivers/staging/comedi/comedi_fops.c
@@ -1980,38 +1980,25 @@ static ssize_t comedi_read(struct file *file, char __user *buf, size_t nbytes,
        DECLARE_WAITQUEUE(wait, current);
        const unsigned minor = iminor(file->f_dentry->d_inode);
        struct comedi_file_info *info = comedi_file_info_from_minor(minor);
-       struct comedi_device *dev;
+       struct comedi_device *dev = comedi_dev_from_minor(minor);
 
-       if (info == NULL)
-               return -ENODEV;
-       dev = info->device;
-       if (dev == NULL)
+       if (!dev)
                return -ENODEV;
 
        if (!dev->attached) {
                DPRINTK("no driver configured on comedi%i\n", dev->minor);
-               retval = -ENODEV;
-               goto done;
+               return -ENODEV;
        }
 
        s = comedi_read_subdevice(info);
-       if (s == NULL) {
-               retval = -EIO;
-               goto done;
-       }
+       if (!s)
+               return -EIO;
+
        async = s->async;
-       if (!nbytes) {
-               retval = 0;
-               goto done;
-       }
-       if (!s->busy) {
-               retval = 0;
-               goto done;
-       }
-       if (s->busy != file) {
-               retval = -EACCES;
-               goto done;
-       }
+       if (!s->busy || !nbytes)
+               return 0;
+       if (s->busy != file)
+               return -EACCES;
 
        add_wait_queue(&async->wait_head, &wait);
        while (nbytes > 0 && !retval) {
@@ -2080,7 +2067,6 @@ static ssize_t comedi_read(struct file *file, char __user *buf, size_t nbytes,
        set_current_state(TASK_RUNNING);
        remove_wait_queue(&async->wait_head, &wait);
 
-done:
        return count ? count : retval;
 }