staging: comedi: range: tidy up comedi_check_chanlist()

The only difference in the if() and else if() check of the chanlist
is the source of the range table length. Consolidate the checks to
make the function a bit more concise.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/comedi/range.c b/drivers/staging/comedi/range.c
index 1f20332cc45921c54fdc4b4ebf61e64119d1b6d8..8fde55495d34bf60e7a83d6f690802f86e79ef76 100644 (file)
--- a/drivers/staging/comedi/range.c
+++ b/drivers/staging/comedi/range.c
@@ -127,38 +127,35 @@ static int aref_invalid(struct comedi_subdevice *s, unsigned int chanspec)
        return 1;
 }
 
-/*
-   This function checks each element in a channel/gain list to make
-   make sure it is valid.
+/**
+ * comedi_check_chanlist() - Validate each element in a chanlist.
+ * @s: comedi_subdevice struct
+ * @n: number of elements in the chanlist
+ * @chanlist: the chanlist to validate
 */
 int comedi_check_chanlist(struct comedi_subdevice *s, int n,
                          unsigned int *chanlist)
 {
        struct comedi_device *dev = s->device;
-       int i;
-       int chan;
+       unsigned int chanspec;
+       int chan, range_len, i;
 
-       if (s->range_table) {
-               for (i = 0; i < n; i++)
-                       if (CR_CHAN(chanlist[i]) >= s->n_chan ||
-                           CR_RANGE(chanlist[i]) >= s->range_table->length
-                           || aref_invalid(s, chanlist[i])) {
-                               dev_warn(dev->class_dev,
-                                        "bad chanlist[%d]=0x%08x in_chan=%d range length=%d\n",
-                                        i, chanlist[i], s->n_chan,
-                                        s->range_table->length);
-                               return -EINVAL;
-                       }
-       } else if (s->range_table_list) {
+       if (s->range_table || s->range_table_list) {
                for (i = 0; i < n; i++) {
-                       chan = CR_CHAN(chanlist[i]);
+                       chanspec = chanlist[i];
+                       chan = CR_CHAN(chanspec);
+                       if (s->range_table)
+                               range_len = s->range_table->length;
+                       else if (s->range_table_list && chan < s->n_chan)
+                               range_len = s->range_table_list[chan]->length;
+                       else
+                               range_len = 0;
                        if (chan >= s->n_chan ||
-                           CR_RANGE(chanlist[i]) >=
-                           s->range_table_list[chan]->length
-                           || aref_invalid(s, chanlist[i])) {
+                           CR_RANGE(chanspec) >= range_len ||
+                           aref_invalid(s, chanspec)) {
                                dev_warn(dev->class_dev,
-                                        "bad chanlist[%d]=0x%08x\n",
-                                        i, chanlist[i]);
+                                        "bad chanlist[%d]=0x%08x chan=%d range length=%d\n",
+                                        i, chanspec, chan, range_len);
                                return -EINVAL;
                        }
                }