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staging: comedi: usbduxsigma: round down AI scan_begin_arg at step 4.

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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 AI subdevice (`usbduxsigma_ai_cmdtest()`)
currently modifies `cmd->scan_begin_arg` to bring it into range and
round it down at step 3.  Move the rounding down part to step 4 to
follow the usual Comedi convention.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: Bernd Porr <mail@berndporr.me.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Ian Abbott 2015-07-23 16:47:00 +01:00 committed by Greg Kroah-Hartman
parent 12e1e69601
commit 333e40aee3
1 changed files with 8 additions and 5 deletions
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13
drivers/staging/comedi/drivers/usbduxsigma.c
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@ -519,17 +519,12 @@ static int usbduxsigma_ai_cmdtest(struct comedi_device *dev,
*/
err |= comedi_check_trigger_arg_min(&cmd->scan_begin_arg,
(125000 * interval));
tmp = (cmd->scan_begin_arg / 125000) * 125000;
} else {
/* full speed */
/* 1kHz scans every USB frame */
err |= comedi_check_trigger_arg_min(&cmd->scan_begin_arg,
1000000);
tmp = (cmd->scan_begin_arg / 1000000) * 1000000;
}
err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, tmp);
err |= comedi_check_trigger_arg_is(&cmd->scan_end_arg,
cmd->chanlist_len);
@ -542,6 +537,14 @@ static int usbduxsigma_ai_cmdtest(struct comedi_device *dev,
if (err)
return 3;
/* Step 4: fix up any arguments */
tmp = rounddown(cmd->scan_begin_arg, high_speed ? 125000 : 1000000);
err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, tmp);
if (err)
return 4;
return 0;
}