diff options
Diffstat (limited to 'drivers/staging/comedi/kcomedilib/kcomedilib_main.c')
-rw-r--r-- | drivers/staging/comedi/kcomedilib/kcomedilib_main.c | 74 |
1 files changed, 46 insertions, 28 deletions
diff --git a/drivers/staging/comedi/kcomedilib/kcomedilib_main.c b/drivers/staging/comedi/kcomedilib/kcomedilib_main.c index cd60677a3ed2..7dc5a18e69d4 100644 --- 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); |