Re: [PATCH] drivers: net: wimax: i2400m: i2400m-usb: Use time_after for time comparison

[Girish Moodalbail]

On 5/8/17 2:26 PM, David Miller wrote:
> From: Karim Eshapa <karim.eshapa@xxxxxxxxx>
> Date: Mon,  8 May 2017 18:58:02 +0200
>
> > diff --git a/drivers/net/wimax/i2400m/i2400m-usb.h b/drivers/net/wimax/i2400m/i2400m-usb.h
> > index 649ecad..6fc941c 100644
> > --- a/drivers/net/wimax/i2400m/i2400m-usb.h
> > +++ b/drivers/net/wimax/i2400m/i2400m-usb.h
> > @@ -131,7 +131,7 @@ static inline int edc_inc(struct edc *edc, u16 max_err, u16 timeframe)
> >  	unsigned long now;
> >
> >  	now = jiffies;
> > -	if (now - edc->timestart > timeframe) {
> > +	if (time_after(now - edc->timestart, (unsigned long)timeframe)) {
>
> This is far from correct.
>
> time_after() compares two "jiffies" timestamp values.  The second
> argument here is not a jiffies timestamp value.

Perhaps, what is needed here is:

+	if (time_after(jiffies, edc->timestart + timeframe)) {

where in 'timeframe' is set in HZ in all the callers I checked (for the most 
part it is set to EDC_ERROR_TIMEFRAME which is 1HZ).

~Girish