diff options
| -rw-r--r-- | arch/i386/kernel/apic.c | 20 | ||||
| -rw-r--r-- | include/asm-i386/apicdef.h | 1 |
2 files changed, 21 insertions, 0 deletions
diff --git a/arch/i386/kernel/apic.c b/arch/i386/kernel/apic.c index eb5279d23b7..3fff3c62d57 100644 --- a/arch/i386/kernel/apic.c +++ b/arch/i386/kernel/apic.c @@ -415,6 +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) { @@ -452,6 +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); diff --git a/include/asm-i386/apicdef.h b/include/asm-i386/apicdef.h index 03185cef8e0..5e4a35af292 100644 --- a/include/asm-i386/apicdef.h +++ b/include/asm-i386/apicdef.h @@ -37,6 +37,7 @@ #define APIC_SPIV_FOCUS_DISABLED (1<<9) #define APIC_SPIV_APIC_ENABLED (1<<8) #define APIC_ISR 0x100 +#define APIC_ISR_NR 0x8 /* Number of 32 bit ISR registers. */ #define APIC_TMR 0x180 #define APIC_IRR 0x200 #define APIC_ESR 0x280 |