10fa1155a2
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>
21 lines
495 B
C
21 lines
495 B
C
#ifndef __UM_DELAY_H
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#define __UM_DELAY_H
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#define MILLION 1000000
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/* Undefined on purpose */
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extern void __bad_udelay(void);
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extern void __udelay(unsigned long usecs);
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extern void __delay(unsigned long loops);
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#define udelay(n) ((__builtin_constant_p(n) && (n) > 20000) ? \
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__bad_udelay() : __udelay(n))
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/* It appears that ndelay is not used at all for UML, and has never been
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* implemented. */
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extern void __unimplemented_ndelay(void);
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#define ndelay(n) __unimplemented_ndelay()
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#endif
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