On 2014-04-15 18:37, H Hartley Sweeten wrote:
Step 5 of the (*do_cmdtest) validates that the chanlist, chan/range/aref/etc,
is compatible with the actual hardware. At this point in the (*do_cmdtest)
the chanlist is valid, due to checks in the core, so the sanity check is not
needed.
For aesthetics, factor the step 5 code into a helper function. Tidy up the
factored out code.
Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Ian Abbott <abbotti@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/comedi/drivers/amplc_pci224.c | 73 ++++++++++++---------------
1 file changed, 32 insertions(+), 41 deletions(-)
diff --git a/drivers/staging/comedi/drivers/amplc_pci224.c b/drivers/staging/comedi/drivers/amplc_pci224.c
index 9f0c20f..eea27e6 100644
--- a/drivers/staging/comedi/drivers/amplc_pci224.c
+++ b/drivers/staging/comedi/drivers/amplc_pci224.c
@@ -687,6 +687,36 @@ pci224_ao_inttrig_start(struct comedi_device *dev, struct comedi_subdevice *s,
return 1;
}
+static int pci224_ao_check_chanlist(struct comedi_device *dev,
+ struct comedi_subdevice *s,
+ struct comedi_cmd *cmd)
+{
+ unsigned int range0 = CR_RANGE(cmd->chanlist[0]);
+ unsigned int chan_mask = 0;
+ int i;
+
+ for (i = 0; i < cmd->chanlist_len; i++) {
+ unsigned int chan = CR_CHAN(cmd->chanlist[i]);
+ unsigned int range = CR_RANGE(cmd->chanlist[i]);
+
+ if (chan_mask & (1 << chan)) {
+ dev_dbg(dev->class_dev,
+ "%s: chanlist must contain no duplicate channels\n",
+ __func__);
+ return -EINVAL;
+ }
+ chan_mask |= (1 << chan);
+
+ if (range != range0) {
+ dev_dbg(dev->class_dev,
+ "%s: chanlist must all have the same range index\n",
+ __func__);
+ return -EINVAL;
+ }
+ }
+ return 0;
+}
+
#define MAX_SCAN_PERIOD 0xFFFFFFFFU
#define MIN_SCAN_PERIOD 2500
#define CONVERT_PERIOD 625
@@ -871,48 +901,9 @@ pci224_ao_cmdtest(struct comedi_device *dev, struct comedi_subdevice *s,
if (err)
return 4;
- /* Step 5: check channel list. */
+ /* Step 5: check channel list */
- if (cmd->chanlist && (cmd->chanlist_len > 0)) {
- unsigned int range;
- enum { range_err = 1, dupchan_err = 2, };
- unsigned errors;
- unsigned int n;
- unsigned int ch;
-
- /*
- * Check all channels have the same range index. Don't care
- * about analogue reference, as we can't configure it.
- *
- * Check the list has no duplicate channels.
- */
- range = CR_RANGE(cmd->chanlist[0]);
- errors = 0;
- tmp = 0;
- for (n = 0; n < cmd->chanlist_len; n++) {
- ch = CR_CHAN(cmd->chanlist[n]);
- if (tmp & (1U << ch))
- errors |= dupchan_err;
-
- tmp |= (1U << ch);
- if (CR_RANGE(cmd->chanlist[n]) != range)
- errors |= range_err;
-
- }
- if (errors) {
- if (errors & dupchan_err) {
- dev_dbg(dev->class_dev,
- "%s: entries in chanlist must contain no duplicate channels\n",
- __func__);
- }
- if (errors & range_err) {
- dev_dbg(dev->class_dev,
- "%s: entries in chanlist must all have the same range index\n",
- __func__);
- }
- err++;
- }
- }
+ err |= pci224_ao_check_chanlist(dev, s, cmd);
if (err)
return 5;
As for the remarks in patch 02, it's possible for chanlist to be NULL or
for chanlist_len to be 0, so pci224_ao_check_chanlist() should only be
called if chanlist is non-NULL and chanlist_len is non-0.
But if chanlist is forced to be NULL by __comedi_get_user_chanlist()
when chanlist_len is 0, it would be sufficient to check that chanlist is
non-NULL before calling pci224_ao_check_chanlist().
--
-=( Ian Abbott @ MEV Ltd. E-mail: <abbotti@xxxxxxxxx> )=-
-=( Tel: +44 (0)161 477 1898 FAX: +44 (0)161 718 3587 )=-
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