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authorAtsushi 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
commitf12555d24ca636569b51c6f104aab41b2bba8c32 (patch)
tree7fa3b59cf1d8a2d11212bcdda76defecbc5076cc /include/asm-mips/delay.h
parent6c35585273b26a580b2e2ad3d6a7db282308eec5 (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>
Diffstat (limited to 'include/asm-mips/delay.h')
-rw-r--r--include/asm-mips/delay.h6
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 */