The `insn_write` handler for the AO subdevice
(`cb_pcidda_ao_insn_write()`) currently ignores `insn->n` (the number of
samples to write) and assumes a single sample is to be written. But
`insn->n` could be 0, meaning no samples should be written, in which
case `data[0]` is invalid.
Follow the usual Comedi guidelines and change
`cb_pcidda_ao_insn_write()` to write the specified number of samples.
This fixes the assumption that `data[0]` is valid.
Signed-off-by: Ian Abbott <abbo...@mev.co.uk>
---
drivers/staging/comedi/drivers/cb_pcidda.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/staging/comedi/drivers/cb_pcidda.c
b/drivers/staging/comedi/drivers/cb_pcidda.c
index 807a31e75883..1d09dd265ab7 100644
--- a/drivers/staging/comedi/drivers/cb_pcidda.c
+++ b/drivers/staging/comedi/drivers/cb_pcidda.c
@@ -291,6 +291,7 @@ static int cb_pcidda_ao_insn_write(struct comedi_device
*dev,
unsigned int channel = CR_CHAN(insn->chanspec);
unsigned int range = CR_RANGE(insn->chanspec);
unsigned int ctrl;
+ unsigned int i;
if (range != devpriv->ao_range[channel])
cb_pcidda_calibrate(dev, channel, range);
@@ -317,7 +318,8 @@ static int cb_pcidda_ao_insn_write(struct comedi_device
*dev,
outw(ctrl, devpriv->daqio + CB_DDA_DA_CTRL_REG);
- outw(data[0], devpriv->daqio + CB_DDA_DA_DATA_REG(channel));
+ for (i = 0; i < insn->n; i++)
+ outw(data[i], devpriv->daqio + CB_DDA_DA_DATA_REG(channel));
return insn->n;
}
--
2.19.1
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