Re: [RFC PATCH v2 03/14] x86/hpet: Calculate ticks-per-second in a separate function

[Ricardo Neri]

On Tue, Mar 26, 2019 at 10:03:02PM +0100, Thomas Gleixner wrote:
> On Wed, 27 Feb 2019, Ricardo Neri wrote:
> >  int hpet_alloc(struct hpet_data *hdp)
> >  {
> >  	u64 cap, mcfg;
> > @@ -845,7 +868,6 @@ int hpet_alloc(struct hpet_data *hdp)
> >  	size_t siz;
> >  	struct hpet __iomem *hpet;
> >  	static struct hpets *last;
> > -	unsigned long period;
> >  	unsigned long long temp;
> >  	u32 remainder;
> >  
> > @@ -881,6 +903,8 @@ int hpet_alloc(struct hpet_data *hdp)
> >  
> >  	cap = readq(&hpet->hpet_cap);
> >  
> > +	temp = hpet_get_ticks_per_sec(cap);
> 
> Just putting stuff to random places does not make the code any better.

This seems to not be needed. I'll remove it and directly save the result
in hpetp->hp_tick_freq;

> 
> >  	ntimer = ((cap & HPET_NUM_TIM_CAP_MASK) >> HPET_NUM_TIM_CAP_SHIFT) + 1;
> >  
> >  	if (hpetp->hp_ntimer != ntimer) {
> > @@ -897,11 +921,6 @@ int hpet_alloc(struct hpet_data *hdp)
> >  
> >  	last = hpetp;
> >  
> > -	period = (cap & HPET_COUNTER_CLK_PERIOD_MASK) >>
> > -		HPET_COUNTER_CLK_PERIOD_SHIFT; /* fs, 10^-15 */
> > -	temp = 1000000000000000uLL; /* 10^15 femtoseconds per second */
> > -	temp += period >> 1; /* round */
> > -	do_div(temp, period);
> >  	hpetp->hp_tick_freq = temp; /* ticks per second */
> 
> What's wrong with the obvious:
> 
>        hpetp->hp_tick_freq = hpet_get_ticks_per_sec(cap);
> 
> Hmm?

Nothing wrong. I'll implement this change.

Thanks and BR,
Ricardo