diff options
| author |   Atsushi Nemoto <anemo@mba.ocn.ne.jp> | 2005-11-30 13:33:26 +0900 |
|---|---|---|
| committer |   <ralf@denk.linux-mips.net> | 2006-01-10 13:39:04 +0000 |
| commit | f12555d24ca636569b51c6f104aab41b2bba8c32 (patch) | |
| tree | 7fa3b59cf1d8a2d11212bcdda76defecbc5076cc /include/asm-mips | |
| parent | MIPS: DSP: eleminate used_dsp. (diff) | |
| download | linux-dev-f12555d24ca636569b51c6f104aab41b2bba8c32.tar.xz linux-dev-f12555d24ca636569b51c6f104aab41b2bba8c32.zip | |
MIPS: Fix mdelay(1) for 64bit kernel with HZ == 1000
mdelay(1) (i.e. udelay(1000)) does not work correctly due to overflow.
1000 * 0x004189374BC6A7f0 = 0x10000000000000180 (>= 2**64)
0x004189374BC6A7ef (0x004189374BC6A7f0 - 1) is OK and it is exactly
same as catchall case (0x8000000000000000UL / (500000 / HZ)).
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'include/asm-mips')
| -rw-r--r-- | include/asm-mips/delay.h | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/include/asm-mips/delay.h b/include/asm-mips/delay.h index 48d00cccdafa..64dd45150f64 100644 --- a/include/asm-mips/delay.h +++ b/include/asm-mips/delay.h @@ -52,13 +52,11 @@ static inline void __udelay(unsigned long usecs, unsigned long lpj) unsigned long lo; /* - * The common rates of 1000 and 128 are rounded wrongly by the - * catchall case for 64-bit. Excessive precission? Probably ... + * The rates of 128 is rounded wrongly by the catchall case + * for 64-bit. Excessive precission? Probably ... */ #if defined(CONFIG_64BIT) && (HZ == 128) usecs *= 0x0008637bd05af6c7UL; /* 2**64 / (1000000 / HZ) */ -#elif defined(CONFIG_64BIT) && (HZ == 1000) - usecs *= 0x004189374BC6A7f0UL; /* 2**64 / (1000000 / HZ) */ #elif defined(CONFIG_64BIT) usecs *= (0x8000000000000000UL / (500000 / HZ)); #else /* 32-bit junk follows here */ |