staging: comedi: drivers (core): don't BUG_ON due to faulty drivers

The postconfig for drivers that support async commands currently can
BUG_ON if the subdevice was improperly configured by the driver.

Change the BUG_ON so that a dev_warn() is output and the postconfig
returns -EINVAL. This will prevent the comedi core from attaching to
the faulty driver but does not BUG the kernel.

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/drivers.c b/drivers/staging/comedi/drivers.c
index e5fe2e1..7e8ee5d 100644 (file)
--- a/drivers/staging/comedi/drivers.c
+++ b/drivers/staging/comedi/drivers.c
@@ -178,8 +178,16 @@ static int __comedi_device_postconfig_async(struct comedi_device *dev,
        unsigned int buf_size;
        int ret;
 
-       BUG_ON((s->subdev_flags & (SDF_CMD_READ | SDF_CMD_WRITE)) == 0);
-       BUG_ON(!s->do_cmdtest);
+       if ((s->subdev_flags & (SDF_CMD_READ | SDF_CMD_WRITE)) == 0) {
+               dev_warn(dev->class_dev,
+                        "async subdevices must support SDF_CMD_READ or SDF_CMD_WRITE\n");
+               return -EINVAL;
+       }
+       if (!s->do_cmdtest) {
+               dev_warn(dev->class_dev,
+                        "async subdevices must have a do_cmdtest() function\n");
+               return -EINVAL;
+       }
 
        async = kzalloc(sizeof(*async), GFP_KERNEL);
        if (!async) {