Call `comedi_dev_get_from_minor()` instead of `comedi_dev_from_minor()` in the sysfs attribute handler functions to increment the reference of the `struct comedi_device` during the operation. Call `comedi_dev_put()` to decrement the reference afterwards. Signed-off-by: Ian Abbott <abbotti@xxxxxxxxx> --- drivers/staging/comedi/comedi_fops.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c index 0ff6913..37400e8 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -328,7 +328,7 @@ static ssize_t max_read_buffer_kb_show(struct device *csdev, struct comedi_subdevice *s; unsigned int size = 0; - dev = comedi_dev_from_minor(minor); + dev = comedi_dev_get_from_minor(minor); if (!dev) return -ENODEV; @@ -338,6 +338,7 @@ static ssize_t max_read_buffer_kb_show(struct device *csdev, size = s->async->max_bufsize / 1024; mutex_unlock(&dev->mutex); + comedi_dev_put(dev); return snprintf(buf, PAGE_SIZE, "%i\n", size); } @@ -358,7 +359,7 @@ static ssize_t max_read_buffer_kb_store(struct device *csdev, return -EINVAL; size *= 1024; - dev = comedi_dev_from_minor(minor); + dev = comedi_dev_get_from_minor(minor); if (!dev) return -ENODEV; @@ -370,6 +371,7 @@ static ssize_t max_read_buffer_kb_store(struct device *csdev, err = -EINVAL; mutex_unlock(&dev->mutex); + comedi_dev_put(dev); return err ? err : count; } static DEVICE_ATTR_RW(max_read_buffer_kb); @@ -382,7 +384,7 @@ static ssize_t read_buffer_kb_show(struct device *csdev, struct comedi_subdevice *s; unsigned int size = 0; - dev = comedi_dev_from_minor(minor); + dev = comedi_dev_get_from_minor(minor); if (!dev) return -ENODEV; @@ -392,6 +394,7 @@ static ssize_t read_buffer_kb_show(struct device *csdev, size = s->async->prealloc_bufsz / 1024; mutex_unlock(&dev->mutex); + comedi_dev_put(dev); return snprintf(buf, PAGE_SIZE, "%i\n", size); } @@ -412,7 +415,7 @@ static ssize_t read_buffer_kb_store(struct device *csdev, return -EINVAL; size *= 1024; - dev = comedi_dev_from_minor(minor); + dev = comedi_dev_get_from_minor(minor); if (!dev) return -ENODEV; @@ -424,6 +427,7 @@ static ssize_t read_buffer_kb_store(struct device *csdev, err = -EINVAL; mutex_unlock(&dev->mutex); + comedi_dev_put(dev); return err ? err : count; } static DEVICE_ATTR_RW(read_buffer_kb); @@ -437,7 +441,7 @@ static ssize_t max_write_buffer_kb_show(struct device *csdev, struct comedi_subdevice *s; unsigned int size = 0; - dev = comedi_dev_from_minor(minor); + dev = comedi_dev_get_from_minor(minor); if (!dev) return -ENODEV; @@ -447,6 +451,7 @@ static ssize_t max_write_buffer_kb_show(struct device *csdev, size = s->async->max_bufsize / 1024; mutex_unlock(&dev->mutex); + comedi_dev_put(dev); return snprintf(buf, PAGE_SIZE, "%i\n", size); } @@ -467,7 +472,7 @@ static ssize_t max_write_buffer_kb_store(struct device *csdev, return -EINVAL; size *= 1024; - dev = comedi_dev_from_minor(minor); + dev = comedi_dev_get_from_minor(minor); if (!dev) return -ENODEV; @@ -479,6 +484,7 @@ static ssize_t max_write_buffer_kb_store(struct device *csdev, err = -EINVAL; mutex_unlock(&dev->mutex); + comedi_dev_put(dev); return err ? err : count; } static DEVICE_ATTR_RW(max_write_buffer_kb); @@ -491,7 +497,7 @@ static ssize_t write_buffer_kb_show(struct device *csdev, struct comedi_subdevice *s; unsigned int size = 0; - dev = comedi_dev_from_minor(minor); + dev = comedi_dev_get_from_minor(minor); if (!dev) return -ENODEV; @@ -501,6 +507,7 @@ static ssize_t write_buffer_kb_show(struct device *csdev, size = s->async->prealloc_bufsz / 1024; mutex_unlock(&dev->mutex); + comedi_dev_put(dev); return snprintf(buf, PAGE_SIZE, "%i\n", size); } @@ -521,7 +528,7 @@ static ssize_t write_buffer_kb_store(struct device *csdev, return -EINVAL; size *= 1024; - dev = comedi_dev_from_minor(minor); + dev = comedi_dev_get_from_minor(minor); if (!dev) return -ENODEV; @@ -533,6 +540,7 @@ static ssize_t write_buffer_kb_store(struct device *csdev, err = -EINVAL; mutex_unlock(&dev->mutex); + comedi_dev_put(dev); return err ? err : count; } static DEVICE_ATTR_RW(write_buffer_kb); -- 1.8.4.2 _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
