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 <abbotti@xxxxxxxxx> --- 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 _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
