diff options
author | Atsushi Nemoto <anemo@mba.ocn.ne.jp> | 2005-11-29 23:33:26 -0500 |
---|---|---|
committer | <ralf@denk.linux-mips.net> | 2006-01-10 08:39:04 -0500 |
commit | f12555d24ca636569b51c6f104aab41b2bba8c32 (patch) | |
tree | 7fa3b59cf1d8a2d11212bcdda76defecbc5076cc | |
parent | 6c35585273b26a580b2e2ad3d6a7db282308eec5 (diff) |
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>
-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) | |||
52 | unsigned long lo; | 52 | unsigned long lo; |
53 | 53 | ||
54 | /* | 54 | /* |
55 | * The common rates of 1000 and 128 are rounded wrongly by the | 55 | * The rates of 128 is rounded wrongly by the catchall case |
56 | * catchall case for 64-bit. Excessive precission? Probably ... | 56 | * for 64-bit. Excessive precission? Probably ... |
57 | */ | 57 | */ |
58 | #if defined(CONFIG_64BIT) && (HZ == 128) | 58 | #if defined(CONFIG_64BIT) && (HZ == 128) |
59 | usecs *= 0x0008637bd05af6c7UL; /* 2**64 / (1000000 / HZ) */ | 59 | usecs *= 0x0008637bd05af6c7UL; /* 2**64 / (1000000 / HZ) */ |
60 | #elif defined(CONFIG_64BIT) && (HZ == 1000) | ||
61 | usecs *= 0x004189374BC6A7f0UL; /* 2**64 / (1000000 / HZ) */ | ||
62 | #elif defined(CONFIG_64BIT) | 60 | #elif defined(CONFIG_64BIT) |
63 | usecs *= (0x8000000000000000UL / (500000 / HZ)); | 61 | usecs *= (0x8000000000000000UL / (500000 / HZ)); |
64 | #else /* 32-bit junk follows here */ | 62 | #else /* 32-bit junk follows here */ |