From f12555d24ca636569b51c6f104aab41b2bba8c32 Mon Sep 17 00:00:00 2001 From: Atsushi Nemoto Date: Wed, 30 Nov 2005 13:33:26 +0900 Subject: [PATCH] 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 Signed-off-by: Ralf Baechle --- include/asm-mips/delay.h | 6 ++---- 1 file 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 */ -- 2.20.1