Re: [PATCH 05/21] atm: he: use mdelay instead of large udelay constants

chas williams - CONTRACTOR
2013-04-26T13:32:52Z

On Fri, 26 Apr 2013 09:21:59 +0100
"David Laight" <David.Laight@ACULAB.COM> wrote:

> > ARM cannot handle udelay for more than 2 miliseconds, so we
> > should use mdelay instead for those.
> ...
> > @@ -1055,7 +1055,7 @@ static int he_start(struct atm_dev *dev)
> > he_writel(he_dev, 0x0, RESET_CNTL);
> > he_writel(he_dev, 0xff, RESET_CNTL);
> >
> > - udelay(16*1000); /* 16 ms */
> > + mdelay(16); /* 16 ms */
> > status = he_readl(he_dev, RESET_CNTL);
>
> 16ms seems a long time to spin.
> I'd have thought a sleep would be more appropriate.
> Since this looks like timing a hardware reset pulse
> it can't matter if it is somewhat longer.

Yes, I wrote this bit some time ago when I was less wise. The
programmer's guide doesn't say how long to sleep, so the value isn't
critical. It just has to be "long enough". An msleep() would be fine
here.