* [PATCH] define MAX_UDELAY_MS
@ 2005-11-04 17:02 Atsushi Nemoto
2005-11-04 17:18 ` Ralf Baechle
0 siblings, 1 reply; 2+ messages in thread
From: Atsushi Nemoto @ 2005-11-04 17:02 UTC (permalink / raw)
To: linux-mips; +Cc: ralf
If HZ was 1000, mdelay(2) cause overflow on multiplication in
__udelay. We should define MAX_UDELAY_MS properly to prevent this.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
diff --git a/include/asm-mips/delay.h b/include/asm-mips/delay.h
--- a/include/asm-mips/delay.h
+++ b/include/asm-mips/delay.h
@@ -84,4 +84,13 @@ static inline void __udelay(unsigned lon
#define udelay(usecs) __udelay((usecs),__udelay_val)
+/* make sure "usecs *= ..." in udelay do not overflow. */
+#if HZ >= 1000
+#define MAX_UDELAY_MS 1
+#elif HZ <= 200
+#define MAX_UDELAY_MS 5
+#else
+#define MAX_UDELAY_MS (1000 / HZ)
+#endif
+
#endif /* _ASM_DELAY_H */
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH] define MAX_UDELAY_MS
2005-11-04 17:02 [PATCH] define MAX_UDELAY_MS Atsushi Nemoto
@ 2005-11-04 17:18 ` Ralf Baechle
0 siblings, 0 replies; 2+ messages in thread
From: Ralf Baechle @ 2005-11-04 17:18 UTC (permalink / raw)
To: Atsushi Nemoto; +Cc: linux-mips
On Sat, Nov 05, 2005 at 02:02:54AM +0900, Atsushi Nemoto wrote:
> If HZ was 1000, mdelay(2) cause overflow on multiplication in
> __udelay. We should define MAX_UDELAY_MS properly to prevent this.
Applied,
Ralf
^ permalink raw reply [flat|nested] 2+ messages in thread
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