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Diffstat (limited to 'arch/i386/kernel/irq.c')
-rw-r--r--arch/i386/kernel/irq.c22
1 files changed, 18 insertions, 4 deletions
diff --git a/arch/i386/kernel/irq.c b/arch/i386/kernel/irq.c
index 5785d84103a..0f2ca590bf2 100644
--- a/arch/i386/kernel/irq.c
+++ b/arch/i386/kernel/irq.c
@@ -10,7 +10,6 @@
* io_apic.c.)
*/
-#include <asm/uaccess.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/interrupt.h>
@@ -21,19 +20,34 @@
#include <asm/idle.h>
+#include <asm/apic.h>
+#include <asm/uaccess.h>
+
DEFINE_PER_CPU(irq_cpustat_t, irq_stat) ____cacheline_internodealigned_in_smp;
EXPORT_PER_CPU_SYMBOL(irq_stat);
-#ifndef CONFIG_X86_LOCAL_APIC
/*
* 'what should we do if we get a hw irq event on an illegal vector'.
* each architecture has to answer this themselves.
*/
void ack_bad_irq(unsigned int irq)
{
- printk("unexpected IRQ trap at vector %02x\n", irq);
-}
+ printk(KERN_ERR "unexpected IRQ trap at vector %02x\n", irq);
+
+#ifdef CONFIG_X86_LOCAL_APIC
+ /*
+ * Currently unexpected vectors happen only on SMP and APIC.
+ * We _must_ ack these because every local APIC has only N
+ * irq slots per priority level, and a 'hanging, unacked' IRQ
+ * holds up an irq slot - in excessive cases (when multiple
+ * unexpected vectors occur) that might lock up the APIC
+ * completely.
+ * But only ack when the APIC is enabled -AK
+ */
+ if (cpu_has_apic)
+ ack_APIC_irq();
#endif
+}
#ifdef CONFIG_4KSTACKS
/*