The flag SDF_CMD_READ was missing which gave the error number "-1" during async reads.

diff --git a/comedi/drivers/usbduxfast.c b/comedi/drivers/usbduxfast.c
index f6965cd5d6d24456a0dfe933cf8c7bceb664cfea..347ead59536de09bf056e96e38c512063316fef2 100644 (file)
--- a/comedi/drivers/usbduxfast.c
+++ b/comedi/drivers/usbduxfast.c
@@ -1742,8 +1742,8 @@ static int usbduxfast_attach(comedi_device * dev, comedi_devconfig * it)
        // analog input
        s->type=COMEDI_SUBD_AI;
        // readable and ref is to ground
-       s->subdev_flags=SDF_READABLE|SDF_GROUND;
-       // 8 channels
+       s->subdev_flags=SDF_READABLE|SDF_GROUND|SDF_CMD_READ;
+       // 16 channels
        s->n_chan=16;
        // length of the channellist
        s->len_chanlist=16;