[PATCH 4/6] staging: comedi: usbduxsigma: round down AI scan_begin_arg at step 4.

Bernd Porr mail at berndporr.me.uk
Fri Jul 24 16:58:58 UTC 2015


Reviewed-by: Bernd Porr <mail at berndporr.me.uk>

Ian Abbott wrote:
> 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 at mev.co.uk>
> ---
>  drivers/staging/comedi/drivers/usbduxsigma.c | 13 ++++++++-----
>  1 file changed, 8 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/staging/comedi/drivers/usbduxsigma.c b/drivers/staging/comedi/drivers/usbduxsigma.c
> index 65a0df4..4655048 100644
> --- a/drivers/staging/comedi/drivers/usbduxsigma.c
> +++ b/drivers/staging/comedi/drivers/usbduxsigma.c
> @@ -518,17 +518,12 @@ 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);
> @@ -541,6 +536,14 @@ 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;
>  }
>  

-- 
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