ni_write_caldac() checks the boardinfo 'caldac' array to determine what
caldac is used for a given 'addr'. It then calculates the 'bitstring' and
number of 'bits' used to write a value to that caldac address.
After checking the caldac array, if the number of bits is 0 there is no
caldac associated with the address. If this happens we shouldn't try
writing to the non-existing caldac.
Reported-by: coverity (CID 1192116)
Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Ian Abbott <abbotti@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/comedi/drivers/ni_mio_common.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/staging/comedi/drivers/ni_mio_common.c b/drivers/staging/comedi/drivers/ni_mio_common.c
index c66affd9..69d71f3 100644
--- a/drivers/staging/comedi/drivers/ni_mio_common.c
+++ b/drivers/staging/comedi/drivers/ni_mio_common.c
@@ -4355,6 +4355,10 @@ static void ni_write_caldac(struct comedi_device *dev, int addr, int val)
addr -= caldacs[type].n_chans;
}
+ /* bits will be 0 if there is no caldac for the given addr */
+ if (bits == 0)
+ return;
+
for (bit = 1 << (bits - 1); bit; bit >>= 1) {
ni_writeb(dev, ((bit & bitstring) ? 0x02 : 0), Serial_Command);
udelay(1);
--
2.3.0
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