From 10fa1155a2c3282f421a74fedfad1957e8bdc86c Mon Sep 17 00:00:00 2001
From: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Date: Sun, 1 Apr 2007 23:49:37 -0700
Subject: [PATCH] uml: fix unreasonably long udelay

Currently we have a confused udelay implementation.

* __const_udelay does not accept usecs but xloops in i386 and x86_64
* our implementation requires usecs as arg
* it gets a xloops count when called by asm/arch/delay.h

Bugs related to this (extremely long shutdown times) where reported by some
x86_64 users, especially using Device Mapper.

To hit this bug, a compile-time constant time parameter must be passed -
that's why UML seems to work most times.  Fix this with a simple udelay
implementation.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 arch/um/sys-i386/delay.c   | 11 -----------
 arch/um/sys-x86_64/delay.c | 11 -----------
 2 files changed, 22 deletions(-)

(limited to 'arch')

diff --git a/arch/um/sys-i386/delay.c b/arch/um/sys-i386/delay.c
index 2c11b9770e8..d623e074f41 100644
--- a/arch/um/sys-i386/delay.c
+++ b/arch/um/sys-i386/delay.c
@@ -27,14 +27,3 @@ void __udelay(unsigned long usecs)
 }
 
 EXPORT_SYMBOL(__udelay);
-
-void __const_udelay(unsigned long usecs)
-{
-	int i, n;
-
-	n = (loops_per_jiffy * HZ * usecs) / MILLION;
-        for(i=0;i<n;i++)
-                cpu_relax();
-}
-
-EXPORT_SYMBOL(__const_udelay);
diff --git a/arch/um/sys-x86_64/delay.c b/arch/um/sys-x86_64/delay.c
index 137f4446b43..dee5be66da8 100644
--- a/arch/um/sys-x86_64/delay.c
+++ b/arch/um/sys-x86_64/delay.c
@@ -28,14 +28,3 @@ void __udelay(unsigned long usecs)
 }
 
 EXPORT_SYMBOL(__udelay);
-
-void __const_udelay(unsigned long usecs)
-{
-	unsigned long i, n;
-
-	n = (loops_per_jiffy * HZ * usecs) / MILLION;
-        for(i=0;i<n;i++)
-                cpu_relax();
-}
-
-EXPORT_SYMBOL(__const_udelay);
-- 
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