MIPS: Fix mdelay(1) for 64bit kernel with HZ == 1000 (f12555d2) · Commits · 戴 / test

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>

include/asm-mips/delay.h

+2 −4

Original line number	Diff line number	Diff line
		@@ -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 */

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