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authorPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>2007-04-01 23:49:37 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-04-02 10:06:08 -0700
commit10fa1155a2c3282f421a74fedfad1957e8bdc86c (patch)
tree21ec69d27c0d5e239f9c0eed531dbcdc0f602af2 /include
parent05565b65a5309e3e5c86db1975b57f75661bee8f (diff)
[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>
Diffstat (limited to 'include')
-rw-r--r--include/asm-um/delay.h17
1 files changed, 14 insertions, 3 deletions
diff --git a/include/asm-um/delay.h b/include/asm-um/delay.h
index 0985bda6675..c71e32b6741 100644
--- a/include/asm-um/delay.h
+++ b/include/asm-um/delay.h
@@ -1,9 +1,20 @@
#ifndef __UM_DELAY_H
#define __UM_DELAY_H
-#include "asm/arch/delay.h"
-#include "asm/archparam.h"
-
#define MILLION 1000000
+/* Undefined on purpose */
+extern void __bad_udelay(void);
+
+extern void __udelay(unsigned long usecs);
+extern void __delay(unsigned long loops);
+
+#define udelay(n) ((__builtin_constant_p(n) && (n) > 20000) ? \
+ __bad_udelay() : __udelay(n))
+
+/* It appears that ndelay is not used at all for UML, and has never been
+ * implemented. */
+extern void __unimplemented_ndelay(void);
+#define ndelay(n) __unimplemented_ndelay()
+
#endif