Re: [PATCH RFC] clk: ux500: add range to usleep_range

From: Nicholas Mc Guire
Date: Thu Apr 11 2019 - 09:00:09 EST


On Thu, Apr 11, 2019 at 04:51:25AM -0700, Joe Perches wrote:
> On Thu, 2019-04-11 at 04:56 +0200, Nicholas Mc Guire wrote:
> > On Wed, Apr 10, 2019 at 03:53:51PM -0700, Stephen Boyd wrote:
> > > Quoting Nicholas Mc Guire (2019-04-06 20:13:24)
> > > > Providing a range for usleep_range() allows the hrtimer subsystem to
> > > > coalesce timers - the delay is runtime configurable so a factor 2
> > > > is taken to provide the range.
> > > >
> > > > Signed-off-by: Nicholas Mc Guire <hofrat@xxxxxxxxxxx>
> > > > ---
> > >
> > > I think this driver is in maintenance mode. I'll wait for Ulf to ack or
> > > review this change before applying.
> > >
> > > > diff --git a/drivers/clk/ux500/clk-sysctrl.c b/drivers/clk/ux500/clk-sysctrl.c
> > > > index 7c0403b..a1fa3fb 100644
> > > > --- a/drivers/clk/ux500/clk-sysctrl.c
> > > > +++ b/drivers/clk/ux500/clk-sysctrl.c
> > > > @@ -42,7 +42,7 @@ static int clk_sysctrl_prepare(struct clk_hw *hw)
> > > > clk->reg_bits[0]);
> > > >
> > > > if (!ret && clk->enable_delay_us)
> > > > - usleep_range(clk->enable_delay_us, clk->enable_delay_us);
> > > > + usleep_range(clk->enable_delay_us, clk->enable_delay_us*2);
> > >
> > > Please add space around that multiply.
> > >
> > I can do that but it does not seem common and also checkpatch
> > did not complain about this - now a simple grep -re "\*10" on the
> > kernel shows that it seems more common not to use spaces around *
> > that to use them.
>
> Not really
>
> $ git grep -P '\*\s*10' | grep -oh -P '\*\s*10' | \
> sort | uniq -c | sort -rn | head
> 11800 * 10
> 1705 *10
> 179 * 10
> 74 * 10
> 67 * 10
> 20 * 10
> 20 * 10
> 14 * 10
> 14 * 10
> 12 * 10

yup - my bad - If you restrict it to code lines - its 1:10
not quite sure how I got the first numbers - sloppy check.

hofrat@debian:~/git/linux-next$ grep -re '.*\*\s*10.*;$' * | grep -oh '\*\s*10' | sort | uniq -c | sort -nr | more
8568 * 10
860 *10

Anyway - is there a reason checkpatch will not flag this ?

thx!
hofrat

>
> > Greping specifically for cases using usleep_range()
> > (not that many) it seems more or less evenly devided between space
> > and no space - so the concern is overlooking that factor 2 ?
> >
> > thx!
> > hofrat
>