staging: comedi: usbduxfast: tidy up the conversion timing validation

Cleanup the validation of the cmd->convert_arg to use the same calculation
in the (*do_cmdtest) and the (*do_cmd).

Remove the, then unnecessary, redundant check in the (*do_cmd).

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/drivers/usbduxfast.c b/drivers/staging/comedi/drivers/usbduxfast.c
index e18b14e9abbff6556dec7acda87551b6ab309cf9..ae775964c7d58fe51a9bf3c699954fa035cfdee6 100644 (file)
--- a/drivers/staging/comedi/drivers/usbduxfast.c
+++ b/drivers/staging/comedi/drivers/usbduxfast.c
@@ -359,8 +359,8 @@ static int usbduxfast_ai_cmdtest(struct comedi_device *dev,
                                 struct comedi_cmd *cmd)
 {
        int err = 0;
-       long int steps, tmp;
-       int min_sample_period;
+       unsigned int steps;
+       unsigned int arg;
 
        /* Step 1 : check if triggers are trivially valid */
 
@@ -399,21 +399,20 @@ static int usbduxfast_ai_cmdtest(struct comedi_device *dev,
        err |= comedi_check_trigger_arg_is(&cmd->scan_end_arg,
                                           cmd->chanlist_len);
 
-       if (cmd->chanlist_len == 1)
-               min_sample_period = 1;
-       else
-               min_sample_period = MIN_SAMPLING_PERIOD;
-
-       steps = cmd->convert_arg * 30;
-       if (steps < (min_sample_period * 1000))
-               steps = min_sample_period * 1000;
-
-       if (steps > (MAX_SAMPLING_PERIOD * 1000))
-               steps = MAX_SAMPLING_PERIOD * 1000;
-
-       /* calc arg again */
-       tmp = steps / 30;
-       err |= comedi_check_trigger_arg_is(&cmd->convert_arg, tmp);
+       /*
+        * Validate the conversion timing:
+        * for 1 channel the timing in 30MHz "steps" is:
+        *      steps <= MAX_SAMPLING_PERIOD
+        * for all other chanlist_len it is:
+        *      MIN_SAMPLING_PERIOD <= steps <= MAX_SAMPLING_PERIOD
+        */
+       steps = (cmd->convert_arg * 30) / 1000;
+       if (cmd->chanlist_len !=  1)
+               err |= comedi_check_trigger_arg_min(&steps,
+                                                   MIN_SAMPLING_PERIOD);
+       err |= comedi_check_trigger_arg_max(&steps, MAX_SAMPLING_PERIOD);
+       arg = (steps * 1000) / 30;
+       err |= comedi_check_trigger_arg_is(&cmd->convert_arg, arg);
 
        if (cmd->stop_src == TRIG_COUNT)
                err |= comedi_check_trigger_arg_min(&cmd->stop_arg, 1);
@@ -489,19 +488,6 @@ static int usbduxfast_ai_cmd(struct comedi_device *dev,
 
        steps = (cmd->convert_arg * 30) / 1000;
 
-       if ((steps < MIN_SAMPLING_PERIOD) && (cmd->chanlist_len != 1)) {
-               dev_err(dev->class_dev,
-                       "steps=%ld, scan_begin_arg=%d. Not properly tested by cmdtest?\n",
-                       steps, cmd->scan_begin_arg);
-               up(&devpriv->sem);
-               return -EINVAL;
-       }
-       if (steps > MAX_SAMPLING_PERIOD) {
-               dev_err(dev->class_dev, "sampling rate too low\n");
-               up(&devpriv->sem);
-               return -EINVAL;
-       }
-
        switch (cmd->chanlist_len) {
        case 1:
                /*