Re: [PATCH v6] clocksource:arm_global_timer: Add ARM global timersupport.

From: Thomas Gleixner
Date: Tue Jun 25 2013 - 10:00:37 EST


On Tue, 25 Jun 2013, Srinivas KANDAGATLA wrote:
> On 25/06/13 14:17, Thomas Gleixner wrote:
> > On Tue, 25 Jun 2013, Srinivas KANDAGATLA wrote:
> >> +static void gt_compare_set(unsigned long delta, int periodic)
> >> +{
> >> + u64 counter = gt_counter_read();
> >> + unsigned long ctrl = readl(gt_base + GT_CONTROL);
> >
> > Why are you reading the control register back over and over? All you
> > need to preserve is the GT_CONTROL_TIMER_ENABLE bit. So you can spare
> > that read out and just do
> >
> > ctrl = GT_CONTROL_TIMER_ENABLE;
> > writel(ctrl, gt_base + GT_CONTROL);
>
> Logically you are right we could do as you suggested, However its not
> implicit that which bits are going to be cleared. Its more to do with
> readability of the code.
> If you still insist I can change it.

I'm not insisting. I just pointed out, that you can save cycles in a
hotpath. :)

Thanks,

tglx
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