cb_pcidas64: don't access *data when insn->n == 0

Due to recent change to do_insnlist_ioctl() and do_insn_ioctl(), the
'data' pointer will be NULL when insn->n == 0.  Do not access *data
in this case.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>

diff --git a/comedi/drivers/cb_pcidas64.c b/comedi/drivers/cb_pcidas64.c
index ead9f11c80cc09af7e88b0fea43f68813c278c83..3cb2e4b35081fabc16e1357b7b03976a6a2b73b6 100644 (file)
--- a/comedi/drivers/cb_pcidas64.c
+++ b/comedi/drivers/cb_pcidas64.c
@@ -3200,6 +3200,9 @@ static int ao_winsn(comedi_device * dev, comedi_subdevice * s,
        int chan = CR_CHAN(insn->chanspec);
        int range = CR_RANGE(insn->chanspec);
 
+       if (insn->n == 0)
+               return 0;
+
        // do some initializing
        writew(0, priv(dev)->main_iobase + DAC_CONTROL0_REG);
 
@@ -3227,6 +3230,9 @@ static int ao_winsn(comedi_device * dev, comedi_subdevice * s,
 static int ao_readback_insn(comedi_device * dev, comedi_subdevice * s,
        comedi_insn * insn, lsampl_t * data)
 {
+       if (insn->n == 0)
+               return 0;
+
        data[0] = priv(dev)->ao_value[CR_CHAN(insn->chanspec)];
 
        return 1;
@@ -3699,6 +3705,9 @@ static int calib_write_insn(comedi_device * dev, comedi_subdevice * s,
 {
        int channel = CR_CHAN(insn->chanspec);
 
+       if (insn->n == 0)
+               return 0;
+
        /* return immediately if setting hasn't changed, since
         * programming these things is slow */
        if (priv(dev)->caldac_state[channel] == data[0])
@@ -3714,6 +3723,9 @@ static int calib_read_insn(comedi_device * dev, comedi_subdevice * s,
 {
        unsigned int channel = CR_CHAN(insn->chanspec);
 
+       if (insn->n == 0)
+               return 0;
+
        data[0] = priv(dev)->caldac_state[channel];
 
        return 1;
@@ -3755,6 +3767,9 @@ static int ad8402_write_insn(comedi_device * dev, comedi_subdevice * s,
 {
        int channel = CR_CHAN(insn->chanspec);
 
+       if (insn->n == 0)
+               return 0;
+
        /* return immediately if setting hasn't changed, since
         * programming these things is slow */
        if (priv(dev)->ad8402_state[channel] == data[0])
@@ -3772,6 +3787,9 @@ static int ad8402_read_insn(comedi_device * dev, comedi_subdevice * s,
 {
        unsigned int channel = CR_CHAN(insn->chanspec);
 
+       if (insn->n == 0)
+               return 0;
+
        data[0] = priv(dev)->ad8402_state[channel];
 
        return 1;
@@ -3842,6 +3860,9 @@ static uint16_t read_eeprom(comedi_device * dev, uint8_t address)
 static int eeprom_read_insn(comedi_device * dev, comedi_subdevice * s,
        comedi_insn * insn, lsampl_t * data)
 {
+       if (insn->n == 0)
+               return 0;
+
        data[0] = read_eeprom(dev, CR_CHAN(insn->chanspec));
 
        return 1;