[PATCH 35/48] staging: comedi: dt2814: use comedi_timeout()

[Ian Abbott]

On 2014-02-06 23:49, H Hartley Sweeten wrote:
> Use comedi_timeout() to wait for the analog input end-of-conversion.
>
> Signed-off-by: H Hartley Sweeten <hsweeten at visionengravers.com>
> Cc: Ian Abbott <abbotti at mev.co.uk>
> Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
> ---
>   drivers/staging/comedi/drivers/dt2814.c | 44 +++++++++++++++++++--------------
>   1 file changed, 26 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/staging/comedi/drivers/dt2814.c b/drivers/staging/comedi/drivers/dt2814.c
> index abad6e4..59c3746 100644
> --- a/drivers/staging/comedi/drivers/dt2814.c
> +++ b/drivers/staging/comedi/drivers/dt2814.c
> @@ -66,26 +66,35 @@ struct dt2814_private {
>   #define DT2814_TIMEOUT 10
>   #define DT2814_MAX_SPEED 100000	/* Arbitrary 10 khz limit */
>
> +static int dt2814_ai_eoc(struct comedi_device *dev,
> +			 struct comedi_subdevice *s,
> +			 struct comedi_insn *insn,
> +			 unsigned long context)
> +{
> +	unsigned int status;
> +
> +	status = inb(dev->iobase + DT2814_CSR);
> +	if (status & DT2814_FINISH)
> +		return 0;
> +	return -EBUSY;
> +}
> +
>   static int dt2814_ai_insn_read(struct comedi_device *dev,
>   			       struct comedi_subdevice *s,
>   			       struct comedi_insn *insn, unsigned int *data)
>   {
> -	int n, i, hi, lo;
> +	int n, hi, lo;
>   	int chan;
> -	int status = 0;
> +	int ret;
>
>   	for (n = 0; n < insn->n; n++) {
>   		chan = CR_CHAN(insn->chanspec);
>
>   		outb(chan, dev->iobase + DT2814_CSR);
> -		for (i = 0; i < DT2814_TIMEOUT; i++) {
> -			status = inb(dev->iobase + DT2814_CSR);
> -			udelay(10);
> -			if (status & DT2814_FINISH)
> -				break;
> -		}
> -		if (i >= DT2814_TIMEOUT)
> -			return -ETIMEDOUT;
> +
> +		ret = comedi_timeout(dev, s, insn, dt2814_ai_eoc, 0);
> +		if (ret)
> +			return ret;
>
>   		hi = inb(dev->iobase + DT2814_DATA);
>   		lo = inb(dev->iobase + DT2814_DATA);
> @@ -211,16 +220,15 @@ static irqreturn_t dt2814_interrupt(int irq, void *d)
>   	data = (hi << 4) | (lo >> 4);
>
>   	if (!(--devpriv->ntrig)) {
> -		int i;
> -
>   		outb(0, dev->iobase + DT2814_CSR);
> -		/* note: turning off timed mode triggers another
> -		   sample. */
>
> -		for (i = 0; i < DT2814_TIMEOUT; i++) {
> -			if (inb(dev->iobase + DT2814_CSR) & DT2814_FINISH)
> -				break;
> -		}
> +		/*
> +		 * Note: turning off timed mode triggers another sample.
> +		 * Wait for the conversion to finish then flush the data.
> +		 * We don't have the 'insn' here but it's not needed.
> +		 */
> +		comedi_timeout(dev, s, NULL, dt2814_ai_eoc, 0);
> +

I don't think you can't really rely on jiffies being updated while in 
the interrupt routine.

>   		inb(dev->iobase + DT2814_DATA);
>   		inb(dev->iobase + DT2814_DATA);
>
>


-- 
-=( Ian Abbott @ MEV Ltd.    E-mail: <abbotti at mev.co.uk>        )=-
-=( Tel: +44 (0)161 477 1898   FAX: +44 (0)161 718 3587         )=-