The return value of the `cmdtest` handler for a subdevice checks the
prospective new command in various steps and returns the step number at
which any problem was detected, or 0 if no problem was detected. It is
allowed to modify the command in various ways at each step. Corrections
for out-of-range values are generally made at step 3, and minor
adjustments such as rounding are generally made at step 4.
The `cmdtest` handler for the AO subdevice (`usbduxsigma_ao_cmdtest()`)
currently range checks the timings at step 3. Since the running command
will round down the timings, add code to round them down at step 4.
Signed-off-by: Ian Abbott <abbotti@xxxxxxxxx>
---
drivers/staging/comedi/drivers/usbduxsigma.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/staging/comedi/drivers/usbduxsigma.c b/drivers/staging/comedi/drivers/usbduxsigma.c
index d97253e..e22c374 100644
--- a/drivers/staging/comedi/drivers/usbduxsigma.c
+++ b/drivers/staging/comedi/drivers/usbduxsigma.c
@@ -837,6 +837,7 @@ static int usbduxsigma_ao_cmdtest(struct comedi_device *dev,
struct comedi_cmd *cmd)
{
struct usbduxsigma_private *devpriv = dev->private;
+ unsigned int tmp;
int err = 0;
/* Step 1 : check if triggers are trivially valid */
@@ -888,6 +889,14 @@ static int usbduxsigma_ao_cmdtest(struct comedi_device *dev,
if (err)
return 3;
+ /* Step 4: fix up any arguments */
+
+ tmp = rounddown(cmd->scan_begin_arg, 1000000);
+ err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, tmp);
+
+ if (err)
+ return 4;
+
return 0;
}
--
2.1.4
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