The `insn_read` handler for the calibration subdevice
(`ni_calib_insn_read()`) currently ignores `insn->n` (the number of
samples to read) and assumes a single sample is to be read into
`data[0]`. Fortunately, the Comedi core ensures that `data[]` has a
length of at least 16, so there is no problem with array bounds.
The usual Comedi convention for `insn_read` handlers is to read the same
channel `insn->n` times into successive elements of `data[]`, so let's
do that.
Also, follow the usual Comedi convention and return `insn->n` from the
handler to indicate success (although any non-negative value will do).
Signed-off-by: Ian Abbott <abbotti@xxxxxxxxx>
---
drivers/staging/comedi/drivers/ni_mio_common.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/comedi/drivers/ni_mio_common.c b/drivers/staging/comedi/drivers/ni_mio_common.c
index 613b6b2abf7d..e008095436d7 100644
--- a/drivers/staging/comedi/drivers/ni_mio_common.c
+++ b/drivers/staging/comedi/drivers/ni_mio_common.c
@@ -4409,10 +4409,12 @@ static int ni_calib_insn_read(struct comedi_device *dev,
unsigned int *data)
{
struct ni_private *devpriv = dev->private;
+ unsigned int i;
- data[0] = devpriv->caldacs[CR_CHAN(insn->chanspec)];
+ for (i = 0; i < insn->n; i++)
+ data[0] = devpriv->caldacs[CR_CHAN(insn->chanspec)];
- return 1;
+ return insn->n;
}
static void caldac_setup(struct comedi_device *dev, struct comedi_subdevice *s)
--
2.20.1
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