diff options
| -rw-r--r-- | drivers/comedi/drivers/dt2815.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/comedi/drivers/dt2815.c b/drivers/comedi/drivers/dt2815.c index 03ba2fd18a21..d066dc303520 100644 --- a/drivers/comedi/drivers/dt2815.c +++ b/drivers/comedi/drivers/dt2815.c @@ -175,6 +175,18 @@ static int dt2815_attach(struct comedi_device *dev, struct comedi_devconfig *it) ? current_range_type : voltage_range_type; } + /* + * Check if hardware is present before attempting any I/O operations. + * Reading 0xff from status register typically indicates no hardware + * on the bus (floating bus reads as all 1s). + */ + if (inb(dev->iobase + DT2815_STATUS) == 0xff) { + dev_err(dev->class_dev, + "No hardware detected at I/O base 0x%lx\n", + dev->iobase); + return -ENODEV; + } + /* Init the 2815 */ outb(0x00, dev->iobase + DT2815_STATUS); for (i = 0; i < 100; i++) { |