Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: [PATCH 3/5] intel_pstate: Fix fixed point rounding macro | Date | Mon, 12 May 2014 14:17:43 +0200 |
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On Thursday, May 08, 2014 12:57:25 PM dirk.brandewie@gmail.com wrote: > From: Dirk Brandewie <dirk.j.brandewie@intel.com> > > Change the FP_ROUNDUP macro to add 0.5 in fixed point representation > instead of 1.0
It would be good to say why exactly it is a problem too. I guess it overflows sometimes, right?
> Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com> > --- > drivers/cpufreq/intel_pstate.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c > index eab8ccf..bb20881 100644 > --- a/drivers/cpufreq/intel_pstate.c > +++ b/drivers/cpufreq/intel_pstate.c > @@ -43,7 +43,7 @@ > #define FRAC_BITS 6 > #define int_tofp(X) ((int64_t)(X) << FRAC_BITS) > #define fp_toint(X) ((X) >> FRAC_BITS) > -#define FP_ROUNDUP(X) ((X) += 1 << FRAC_BITS) > +#define FP_ROUNDUP(X) ((X) += 1 << (FRAC_BITS-1)) > > static inline int32_t mul_fp(int32_t x, int32_t y) > { >
-- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.
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