diff options
| -rw-r--r-- | include/asm-powerpc/delay.h | 13 | ||||
| -rw-r--r-- | include/linux/delay.h | 5 |
2 files changed, 14 insertions, 4 deletions
diff --git a/include/asm-powerpc/delay.h b/include/asm-powerpc/delay.h index 057a6095547..f9200a65c63 100644 --- a/include/asm-powerpc/delay.h +++ b/include/asm-powerpc/delay.h @@ -17,5 +17,18 @@ extern void __delay(unsigned long loops); extern void udelay(unsigned long usecs); +/* + * On shared processor machines the generic implementation of mdelay can + * result in large errors. While each iteration of the loop inside mdelay + * is supposed to take 1ms, the hypervisor could sleep our partition for + * longer (eg 10ms). With the right timing these errors can add up. + * + * Since there is no 32bit overflow issue on 64bit kernels, just call + * udelay directly. + */ +#ifdef CONFIG_PPC64 +#define mdelay(n) udelay((n) * 1000) +#endif + #endif /* __KERNEL__ */ #endif /* _ASM_POWERPC_DELAY_H */ diff --git a/include/linux/delay.h b/include/linux/delay.h index acb74865b97..17ddb55430a 100644 --- a/include/linux/delay.h +++ b/include/linux/delay.h @@ -25,10 +25,7 @@ extern unsigned long loops_per_jiffy; #define MAX_UDELAY_MS 5 #endif -#ifdef notdef -#define mdelay(n) (\ - {unsigned long __ms=(n); while (__ms--) udelay(1000);}) -#else +#ifndef mdelay #define mdelay(n) (\ (__builtin_constant_p(n) && (n)<=MAX_UDELAY_MS) ? udelay((n)*1000) : \ ({unsigned long __ms=(n); while (__ms--) udelay(1000);})) |