[PATCH 45/79] [PATCH] fix apic acking of irqs

From: Glauber de Oliveira Costa
Date: Wed Mar 19 2008 - 16:01:40 EST


From: Glauber Costa <gcosta@xxxxxxxxxx>

EOI is a write-only register. Using write around will have the effect
of reading it, which will make all subsequent reads of the ESR register
to return an error code. It was unnotices for quite a while because main sources
of reading the ESR register where done prior to apic interrupt enabling.

Signed-off-by: Glauber Costa <gcosta@xxxxxxxxxx>
---
include/asm-x86/apic.h | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/include/asm-x86/apic.h b/include/asm-x86/apic.h
index db5f750..0d6ea74 100644
--- a/include/asm-x86/apic.h
+++ b/include/asm-x86/apic.h
@@ -103,7 +103,7 @@ static inline void ack_APIC_irq(void)
*/

/* Docs say use 0 for future compatibility */
- apic_write_around(APIC_EOI, 0);
+ apic_write(APIC_EOI, 0);
}

extern int lapic_get_maxlvt(void);
--
1.5.0.6

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