diff options
| -rw-r--r-- | arch/blackfin/include/asm/delay.h | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/arch/blackfin/include/asm/delay.h b/arch/blackfin/include/asm/delay.h index 0889c3abb59..47f98c5067b 100644 --- a/arch/blackfin/include/asm/delay.h +++ b/arch/blackfin/include/asm/delay.h @@ -47,16 +47,15 @@ static inline void __delay(unsigned long loops) #include <linux/param.h> /* needed for HZ */ /* - * Use only for very small delays ( < 1 msec). Should probably use a - * lookup table, really, as the multiplications take much too long with - * short delays. This is a "reasonable" implementation, though (and the - * first constant multiplications gets optimized away if the delay is - * a constant) + * close approximation borrowed from m68knommu to avoid 64-bit math */ + +#define HZSCALE (268435456 / (1000000/HZ)) + static inline void udelay(unsigned long usecs) { extern unsigned long loops_per_jiffy; - __delay(usecs * loops_per_jiffy / (1000000 / HZ)); + __delay((((usecs * HZSCALE) >> 11) * (loops_per_jiffy >> 11)) >> 6); } #endif |