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 functions. 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/cb_pcidas.c | 77 +++++++++++++++++++-----------
1 file changed, 49 insertions(+), 28 deletions(-)
diff --git a/drivers/staging/comedi/drivers/cb_pcidas.c b/drivers/staging/comedi/drivers/cb_pcidas.c
index 83a265f..d01cf9a 100644
--- a/drivers/staging/comedi/drivers/cb_pcidas.c
+++ b/drivers/staging/comedi/drivers/cb_pcidas.c
@@ -803,6 +803,32 @@ static int trimpot_read_insn(struct comedi_device *dev,
return 1;
}
+static int cb_pcidas_ai_check_chanlist(struct comedi_device *dev,
+ struct comedi_subdevice *s,
+ struct comedi_cmd *cmd)
+{
+ unsigned int chan0 = CR_CHAN(cmd->chanlist[0]);
+ unsigned int range0 = CR_RANGE(cmd->chanlist[0]);
+ int i;
+
+ for (i = 1; i < cmd->chanlist_len; i++) {
+ unsigned int chan = CR_CHAN(cmd->chanlist[i]);
+ unsigned int range = CR_RANGE(cmd->chanlist[i]);
+
+ if (chan != (chan0 + i) % s->n_chan) {
+ dev_err(dev->class_dev,
+ "chanlist must be consecutive channels, counting upwards\n");
+ return -EINVAL;
+ }
+ if (range != range0) {
+ dev_err(dev->class_dev,
+ "chanlist must all have the same range\n");
+ return -EINVAL;
+ }
+ }
+ return 0;
+}
+
static int cb_pcidas_ai_cmdtest(struct comedi_device *dev,
struct comedi_subdevice *s,
struct comedi_cmd *cmd)
@@ -811,7 +837,6 @@ static int cb_pcidas_ai_cmdtest(struct comedi_device *dev,
struct cb_pcidas_private *devpriv = dev->private;
int err = 0;
int tmp;
- int i, gain, start_chan;
/* Step 1 : check if triggers are trivially valid */
@@ -907,24 +932,9 @@ static int cb_pcidas_ai_cmdtest(struct comedi_device *dev,
if (err)
return 4;
- /* check channel/gain list against card's limitations */
- if (cmd->chanlist) {
- gain = CR_RANGE(cmd->chanlist[0]);
- start_chan = CR_CHAN(cmd->chanlist[0]);
- for (i = 1; i < cmd->chanlist_len; i++) {
- if (CR_CHAN(cmd->chanlist[i]) !=
- (start_chan + i) % s->n_chan) {
- comedi_error(dev,
- "entries in chanlist must be consecutive channels, counting upwards\n");
- err++;
- }
- if (CR_RANGE(cmd->chanlist[i]) != gain) {
- comedi_error(dev,
- "entries in chanlist must all have the same gain\n");
- err++;
- }
- }
- }
+ /* Step 5: check channel list */
+
+ err |= cb_pcidas_ai_check_chanlist(dev, s, cmd);
if (err)
return 5;
@@ -1035,6 +1045,23 @@ static int cb_pcidas_ai_cmd(struct comedi_device *dev,
return 0;
}
As for the remarks in patch 02, it's possible for chanlist to be NULL or
for chanlist_len to be 0, so cb_pcidas_ai_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 cb_pcidas_ai_check_chanlist().
The original code is buggy as well because it accesses cmd->chanlist[0]
without checking cmd->chanlist_len.
+static int cb_pcidas_ao_check_chanlist(struct comedi_device *dev,
+ struct comedi_subdevice *s,
+ struct comedi_cmd *cmd)
+{
+ if (cmd->chanlist_len > 1) {
+ unsigned int chan0 = CR_CHAN(cmd->chanlist[0]);
+ unsigned int chan1 = CR_CHAN(cmd->chanlist[1]);
+
+ if (chan0 != 0 || chan1 != 1) {
+ dev_err(dev->class_dev,
+ "channels must be ordered channel 0, channel 1 in chanlist\n");
+ return -EINVAL;
+ }
+ }
+ return 0;
+}
+
static int cb_pcidas_ao_cmdtest(struct comedi_device *dev,
struct comedi_subdevice *s,
struct comedi_cmd *cmd)
@@ -1097,15 +1124,9 @@ static int cb_pcidas_ao_cmdtest(struct comedi_device *dev,
if (err)
return 4;
- /* check channel/gain list against card's limitations */
- if (cmd->chanlist && cmd->chanlist_len > 1) {
- if (CR_CHAN(cmd->chanlist[0]) != 0 ||
- CR_CHAN(cmd->chanlist[1]) != 1) {
- comedi_error(dev,
- "channels must be ordered channel 0, channel 1 in chanlist\n");
- err++;
- }
- }
+ /* Step 5: check channel list */
+
+ err |= cb_pcidas_ao_check_chanlist(dev, s, cmd);
if (err)
return 5;
Ditto for calling cb_pcidas_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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