diff options
Diffstat (limited to 'arch/x86/kernel/io_apic_32.c')
| -rw-r--r-- | arch/x86/kernel/io_apic_32.c | 20 |
1 files changed, 9 insertions, 11 deletions
diff --git a/arch/x86/kernel/io_apic_32.c b/arch/x86/kernel/io_apic_32.c index a40d54fc1fd..c64b3f5cc12 100644 --- a/arch/x86/kernel/io_apic_32.c +++ b/arch/x86/kernel/io_apic_32.c @@ -2146,19 +2146,17 @@ static inline void __init check_timer(void) set_intr_gate(vector, interrupt[0]); /* - * Subtle, code in do_timer_interrupt() expects an AEOI - * mode for the 8259A whenever interrupts are routed - * through I/O APICs. Also IRQ0 has to be enabled in - * the 8259A which implies the virtual wire has to be - * disabled in the local APIC. Finally timer interrupts - * need to be acknowledged manually in the 8259A for - * timer_interrupt() and for the i82489DX when using - * the NMI watchdog. + * As IRQ0 is to be enabled in the 8259A, the virtual + * wire has to be disabled in the local APIC. Also + * timer interrupts need to be acknowledged manually in + * the 8259A for the i82489DX when using the NMI + * watchdog as that APIC treats NMIs as level-triggered. + * The AEOI mode will finish them in the 8259A + * automatically. */ apic_write_around(APIC_LVT0, APIC_LVT_MASKED | APIC_DM_EXTINT); init_8259A(1); - timer_ack = !cpu_has_tsc; - timer_ack |= (nmi_watchdog == NMI_IO_APIC && !APIC_INTEGRATED(ver)); + timer_ack = (nmi_watchdog == NMI_IO_APIC && !APIC_INTEGRATED(ver)); if (timer_over_8254 > 0) enable_8259A_irq(0); @@ -2219,6 +2217,7 @@ static inline void __init check_timer(void) printk(KERN_WARNING "timer doesn't work through the IO-APIC - disabling NMI Watchdog!\n"); nmi_watchdog = 0; } + timer_ack = 0; printk(KERN_INFO "...trying to set up timer as Virtual Wire IRQ..."); @@ -2237,7 +2236,6 @@ static inline void __init check_timer(void) printk(KERN_INFO "...trying to set up timer as ExtINT IRQ..."); - timer_ack = 0; init_8259A(0); make_8259A_irq(0); apic_write_around(APIC_LVT0, APIC_DM_EXTINT); |