Staging: comedi: ni_65xx.c: fix output inversion problem.

When reading DO subdevice with inverted outputs invert the values read
back from the ports to match the inversion of values written.

Signed-off-by: Frank Mori Hess <fmhess@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/staging/comedi/drivers/ni_65xx.c b/drivers/staging/comedi/drivers/ni_65xx.c
index b664ce0..bbf75eb 100644 (file)
--- a/drivers/staging/comedi/drivers/ni_65xx.c
+++ b/drivers/staging/comedi/drivers/ni_65xx.c
@@ -457,6 +457,12 @@ static int ni_65xx_dio_insn_bits(struct comedi_device *dev,
                port_read_bits =
                    readb(private(dev)->mite->daq_io_addr + Port_Data(port));
 /* printk("read 0x%x from port %i\n", port_read_bits, port); */
+               if (s->type == COMEDI_SUBD_DO && board(dev)->invert_outputs) {
+                       /* Outputs inverted, so invert value read back from
+                        * DO subdevice.  (Does not apply to boards with DIO
+                        * subdevice.) */
+                       port_read_bits ^= 0xFF;
+               }
                if (bitshift > 0) {
                        port_read_bits <<= bitshift;
                } else {