Merge branch 'for-3.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq

[linux-2.6-block.git] / drivers / staging / comedi / kcomedilib / kcomedilib_main.c

diff --git a/drivers/staging/comedi/kcomedilib/kcomedilib_main.c b/drivers/staging/comedi/kcomedilib/kcomedilib_main.c
index cd60677a3ed2f2771120dc5d23597e82a6fd34f9..7dc5a18e69d42bd4bd8e9df3d2458d368f769753 100644 (file)
--- a/drivers/staging/comedi/kcomedilib/kcomedilib_main.c
+++ b/drivers/staging/comedi/kcomedilib/kcomedilib_main.c
@@ -35,7 +35,7 @@ MODULE_LICENSE("GPL");
 
 struct comedi_device *comedi_open(const char *filename)
 {
-       struct comedi_device *dev;
+       struct comedi_device *dev, *retval = NULL;
        unsigned int minor;
 
        if (strncmp(filename, "/dev/comedi", 11) != 0)
@@ -46,24 +46,27 @@ struct comedi_device *comedi_open(const char *filename)
        if (minor >= COMEDI_NUM_BOARD_MINORS)
                return NULL;
 
-       dev = comedi_dev_from_minor(minor);
-
-       if (!dev || !dev->attached)
+       dev = comedi_dev_get_from_minor(minor);
+       if (!dev)
                return NULL;
 
-       if (!try_module_get(dev->driver->module))
-               return NULL;
+       down_read(&dev->attach_lock);
+       if (dev->attached)
+               retval = dev;
+       else
+               retval = NULL;
+       up_read(&dev->attach_lock);
+
+       if (retval == NULL)
+               comedi_dev_put(dev);
 
-       return dev;
+       return retval;
 }
 EXPORT_SYMBOL_GPL(comedi_open);
 
-int comedi_close(struct comedi_device *d)
+int comedi_close(struct comedi_device *dev)
 {
-       struct comedi_device *dev = (struct comedi_device *)d;
-
-       module_put(dev->driver->module);
-
+       comedi_dev_put(dev);
        return 0;
 }
 EXPORT_SYMBOL_GPL(comedi_close);
@@ -73,7 +76,14 @@ static int comedi_do_insn(struct comedi_device *dev,
                          unsigned int *data)
 {
        struct comedi_subdevice *s;
-       int ret = 0;
+       int ret;
+
+       mutex_lock(&dev->mutex);
+
+       if (!dev->attached) {
+               ret = -EINVAL;
+               goto error;
+       }
 
        /* a subdevice instruction */
        if (insn->subdev >= dev->n_subdevices) {
@@ -120,6 +130,7 @@ static int comedi_do_insn(struct comedi_device *dev,
        s->busy = NULL;
 error:
 
+       mutex_unlock(&dev->mutex);
        return ret;
 }
 
@@ -169,9 +180,6 @@ int comedi_dio_bitfield2(struct comedi_device *dev, unsigned int subdev,
        unsigned int shift;
        int ret;
 
-       if (subdev >= dev->n_subdevices)
-               return -EINVAL;
-
        base_channel = CR_CHAN(base_channel);
        n_chan = comedi_get_n_channels(dev, subdev);
        if (base_channel >= n_chan)
@@ -211,23 +219,33 @@ int comedi_find_subdevice_by_type(struct comedi_device *dev, int type,
                                  unsigned int subd)
 {
        struct comedi_subdevice *s;
-
-       if (subd > dev->n_subdevices)
-               return -ENODEV;
-
-       for (; subd < dev->n_subdevices; subd++) {
-               s = &dev->subdevices[subd];
-               if (s->type == type)
-                       return subd;
-       }
-       return -1;
+       int ret = -ENODEV;
+
+       down_read(&dev->attach_lock);
+       if (dev->attached)
+               for (; subd < dev->n_subdevices; subd++) {
+                       s = &dev->subdevices[subd];
+                       if (s->type == type) {
+                               ret = subd;
+                               break;
+                       }
+               }
+       up_read(&dev->attach_lock);
+       return ret;
 }
 EXPORT_SYMBOL_GPL(comedi_find_subdevice_by_type);
 
 int comedi_get_n_channels(struct comedi_device *dev, unsigned int subdevice)
 {
-       struct comedi_subdevice *s = &dev->subdevices[subdevice];
+       int n;
+
+       down_read(&dev->attach_lock);
+       if (!dev->attached || subdevice >= dev->n_subdevices)
+               n = 0;
+       else
+               n = dev->subdevices[subdevice].n_chan;
+       up_read(&dev->attach_lock);
 
-       return s->n_chan;
+       return n;
 }
 EXPORT_SYMBOL_GPL(comedi_get_n_channels);