Set SDF_CMD_READ subdevice flag if do_cmd and do_cmdtest are set.

Only set read_subdev if do_cmd and do_cmdtest are set.
Don't set write_subdev as no subdevice supports write commands.

diff --git a/comedi/drivers/pcl818.c b/comedi/drivers/pcl818.c
index 263dc6a192658cfd1332a435bd74b18c42640465..62595dd13ddbb8a74f0033f25be264170233e914 100644 (file)
--- a/comedi/drivers/pcl818.c
+++ b/comedi/drivers/pcl818.c
@@ -1829,7 +1829,6 @@ static int pcl818_attach(comedi_device * dev, comedi_devconfig * it)
        if (!this_board->n_aichan_se) {
                s->type = COMEDI_SUBD_UNUSED;
        } else {
-               dev->read_subdev = s;
                s->type = COMEDI_SUBD_AI;
                devpriv->sub_ai = s;
                s->subdev_flags = SDF_READABLE;
@@ -1848,6 +1847,8 @@ static int pcl818_attach(comedi_device * dev, comedi_devconfig * it)
                s->cancel = pcl818_ai_cancel;
                s->insn_read = pcl818_ai_insn_read;
                if ((irq) || (devpriv->dma_rtc)) {
+                       dev->read_subdev = s;
+                       s->subdev_flags |= SDF_CMD_READ;
                        s->do_cmdtest = ai_cmdtest;
                        s->do_cmd = ai_cmd;
                }
@@ -1894,7 +1895,6 @@ static int pcl818_attach(comedi_device * dev, comedi_devconfig * it)
        if (!this_board->n_aochan) {
                s->type = COMEDI_SUBD_UNUSED;
        } else {
-               dev->write_subdev = s;
                s->type = COMEDI_SUBD_AO;
                s->subdev_flags = SDF_WRITABLE | SDF_GROUND;
                s->n_chan = this_board->n_aochan;