fixed bug that caused nasty interaction between analog input command and analog outpu...

diff --git a/comedi/drivers/ni_labpc.c b/comedi/drivers/ni_labpc.c
index 6333dd89daf6ac8cf4a100be53f134dfdab4dd64..4ec068a6381a56dea0ecfb8b63e635add3f7811a 100644 (file)
--- a/comedi/drivers/ni_labpc.c
+++ b/comedi/drivers/ni_labpc.c
@@ -466,12 +466,12 @@ typedef struct{
        unsigned int ao_range[NUM_AO_CHAN];     // current ao range settings
        unsigned int ao_value[NUM_AO_CHAN];     // software copy of analog output values
        // software copys of bits written to command registers
-       unsigned int command1_bits;
-       unsigned int command2_bits;
-       unsigned int command3_bits;
-       unsigned int command4_bits;
-       unsigned int command5_bits;
-       unsigned int command6_bits;
+       volatile unsigned int command1_bits;
+       volatile unsigned int command2_bits;
+       volatile unsigned int command3_bits;
+       volatile unsigned int command4_bits;
+       volatile unsigned int command5_bits;
+       volatile unsigned int command6_bits;
        // store last read of board status registers
        volatile unsigned int status1_bits;
        volatile unsigned int status2_bits;
@@ -1534,7 +1534,7 @@ static int labpc_ao_winsn(comedi_device *dev, comedi_subdevice *s,
        channel = CR_CHAN(insn->chanspec);
 
        // turn off pacing of analog output channel
-       devpriv->command2_bits &= DAC_PACED_BIT(channel);
+       devpriv->command2_bits &= ~DAC_PACED_BIT(channel);
        thisboard->write_byte(devpriv->command2_bits, dev->iobase + COMMAND2_REG);
 
        // set range