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-rw-r--r--arch/arm/lib/delay.S20
-rw-r--r--include/asm-arm/delay.h12
2 files changed, 19 insertions, 13 deletions
diff --git a/arch/arm/lib/delay.S b/arch/arm/lib/delay.S
index b3fb475b4120..9183b06c0e2f 100644
--- a/arch/arm/lib/delay.S
+++ b/arch/arm/lib/delay.S
@@ -9,28 +9,32 @@
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
+#include <asm/param.h>
.text
.LC0: .word loops_per_jiffy
+.LC1: .word (2199023*HZ)>>11
/*
- * 0 <= r0 <= 2000
+ * r0 <= 2000
+ * lpj <= 0x01ffffff (max. 3355 bogomips)
+ * HZ <= 1000
*/
+
ENTRY(__udelay)
- mov r2, #0x6800
- orr r2, r2, #0x00db
+ ldr r2, .LC1
mul r0, r2, r0
-ENTRY(__const_udelay) @ 0 <= r0 <= 0x01ffffff
+ENTRY(__const_udelay) @ 0 <= r0 <= 0x7fffff06
ldr r2, .LC0
- ldr r2, [r2] @ max = 0x0fffffff
- mov r0, r0, lsr #11 @ max = 0x00003fff
- mov r2, r2, lsr #11 @ max = 0x0003ffff
+ ldr r2, [r2] @ max = 0x01ffffff
+ mov r0, r0, lsr #14 @ max = 0x0001ffff
+ mov r2, r2, lsr #10 @ max = 0x00007fff
mul r0, r2, r0 @ max = 2^32-1
movs r0, r0, lsr #6
RETINSTR(moveq,pc,lr)
/*
- * loops = (r0 * 0x10c6 * 100 * loops_per_jiffy) / 2^32
+ * loops = r0 * HZ * loops_per_jiffy / 1000000
*
* Oh, if only we had a cycle counter...
*/
diff --git a/include/asm-arm/delay.h b/include/asm-arm/delay.h
index 1704360e9699..b2deda181549 100644
--- a/include/asm-arm/delay.h
+++ b/include/asm-arm/delay.h
@@ -6,6 +6,8 @@
#ifndef __ASM_ARM_DELAY_H
#define __ASM_ARM_DELAY_H
+#include <asm/param.h> /* HZ */
+
extern void __delay(int loops);
/*
@@ -13,7 +15,7 @@ extern void __delay(int loops);
* it, it means that you're calling udelay() with an out of range value.
*
* With currently imposed limits, this means that we support a max delay
- * of 2000us and 671 bogomips
+ * of 2000us. Further limits: HZ<=1000 and bogomips<=3355
*/
extern void __bad_udelay(void);
@@ -32,10 +34,10 @@ extern void __const_udelay(unsigned long);
#define MAX_UDELAY_MS 2
-#define udelay(n) \
- (__builtin_constant_p(n) ? \
- ((n) > (MAX_UDELAY_MS * 1000) ? __bad_udelay() : \
- __const_udelay((n) * 0x68dbul)) : \
+#define udelay(n) \
+ (__builtin_constant_p(n) ? \
+ ((n) > (MAX_UDELAY_MS * 1000) ? __bad_udelay() : \
+ __const_udelay((n) * ((2199023U*HZ)>>11))) : \
__udelay(n))
#endif /* defined(_ARM_DELAY_H) */