From a649a6754d246d5b5447f74b86ed4b947e5f5446 Mon Sep 17 00:00:00 2001 From: Ian Abbott Date: Thu, 4 Apr 2013 14:58:45 +0100 Subject: [PATCH] staging: comedi: adjust module count on device cleanup `comedi_device_cleanup()` is called just before freeing a comedi device. It is possible for the device to still be open in which case the module reference counts for the core comedi module and possibly the low-level driver module will remain out of whack because `comedi_close()` will not find the comedi device and so will not decrement the module counts. This really needs to be handled better, but for now decrement the module counts in `comedi_device_cleanup()` according to the number of outstanding opens. Signed-off-by: Ian Abbott Reviewed-by: H Hartley Sweeten Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/comedi_fops.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c index f2bfa0e..70b2034 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -2256,10 +2256,20 @@ static void comedi_device_init(struct comedi_device *dev) static void comedi_device_cleanup(struct comedi_device *dev) { + struct module *driver_module = NULL; + if (dev == NULL) return; mutex_lock(&dev->mutex); + if (dev->attached) + driver_module = dev->driver->module; comedi_device_detach(dev); + while (dev->use_count > 0) { + if (driver_module) + module_put(driver_module); + module_put(THIS_MODULE); + dev->use_count--; + } mutex_unlock(&dev->mutex); mutex_destroy(&dev->mutex); } -- 2.7.4