1 files changed, 26 insertions, 3 deletions

diff --git a/arch/i386/kernel/apic.c b/arch/i386/kernel/apic.c
index f39e09ef64ec..6273bf74c203 100644
--- a/arch/i386/kernel/apic.c
+++ b/arch/i386/kernel/apic.c
@@ -38,6 +38,7 @@
 #include <asm/i8253.h>
 
 #include <mach_apic.h>
+#include <mach_apicdef.h>
 #include <mach_ipi.h>
 
 #include "io_ports.h"
@@ -414,6 +415,7 @@ void __init init_bsp_APIC(void)
 void __devinit setup_local_APIC(void)
 {
         unsigned long oldvalue, value, ver, maxlvt;
+        int i, j;
 
         /* Pound the ESR really hard over the head with a big hammer - mbligh */
         if (esr_disable) {
@@ -451,6 +453,25 @@ void __devinit setup_local_APIC(void)
         apic_write_around(APIC_TASKPRI, value);
 
         /*
+         * After a crash, we no longer service the interrupts and a pending
+         * interrupt from previous kernel might still have ISR bit set.
+         *
+         * Most probably by now CPU has serviced that pending interrupt and
+         * it might not have done the ack_APIC_irq() because it thought,
+         * interrupt came from i8259 as ExtInt. LAPIC did not get EOI so it
+         * does not clear the ISR bit and cpu thinks it has already serivced
+         * the interrupt. Hence a vector might get locked. It was noticed
+         * for timer irq (vector 0x31). Issue an extra EOI to clear ISR.
+         */
+        for (i = APIC_ISR_NR - 1; i >= 0; i--) {
+                value = apic_read(APIC_ISR + i*0x10);
+                for (j = 31; j >= 0; j--) {
+                        if (value & (1<<j))
+                                ack_APIC_irq();
+                }
+        }
+
+        /*
          * Now that we are all set up, enable the APIC
          */
         value = apic_read(APIC_SPIV);
@@ -570,16 +591,18 @@ void __devinit setup_local_APIC(void)
  */
 void lapic_shutdown(void)
 {
+        unsigned long flags;
+
         if (!cpu_has_apic)
                 return;
 
-        local_irq_disable();
+        local_irq_save(flags);
         clear_local_APIC();
 
         if (enabled_via_apicbase)
                 disable_local_APIC();
 
-        local_irq_enable();
+        local_irq_restore(flags);
 }
 
 #ifdef CONFIG_PM
@@ -729,7 +752,7 @@ static int __init apic_set_verbosity(char *str)
                 printk(KERN_WARNING "APIC Verbosity level %s not recognised"
                                 " use apic=verbose or apic=debug\n", str);
 
-        return 0;
+        return 1;
 }
 
 __setup("apic=", apic_set_verbosity);