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-rw-r--r--arch/x86/kernel/io_apic_32.c20
-rw-r--r--arch/x86/kernel/io_apic_64.c7
-rw-r--r--arch/x86/kernel/nmi_32.c2
-rw-r--r--arch/x86/kernel/time_32.c3
4 files changed, 13 insertions, 19 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);
diff --git a/arch/x86/kernel/io_apic_64.c b/arch/x86/kernel/io_apic_64.c
index ef1a8dfcc52..7c34e38e421 100644
--- a/arch/x86/kernel/io_apic_64.c
+++ b/arch/x86/kernel/io_apic_64.c
@@ -1669,11 +1669,8 @@ static inline void __init check_timer(void)
assign_irq_vector(0, TARGET_CPUS);
/*
- * 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.
+ * As IRQ0 is to be enabled in the 8259A, the virtual
+ * wire has to be disabled in the local APIC.
*/
apic_write(APIC_LVT0, APIC_LVT_MASKED | APIC_DM_EXTINT);
init_8259A(1);
diff --git a/arch/x86/kernel/nmi_32.c b/arch/x86/kernel/nmi_32.c
index 11b14bbaa61..d322901c38e 100644
--- a/arch/x86/kernel/nmi_32.c
+++ b/arch/x86/kernel/nmi_32.c
@@ -131,7 +131,7 @@ int __init check_nmi_watchdog(void)
kfree(prev_nmi_count);
return 0;
error:
- timer_ack = !cpu_has_tsc;
+ timer_ack = 0;
return -1;
}
diff --git a/arch/x86/kernel/time_32.c b/arch/x86/kernel/time_32.c
index 2ff21f39893..5f29f12da50 100644
--- a/arch/x86/kernel/time_32.c
+++ b/arch/x86/kernel/time_32.c
@@ -84,8 +84,7 @@ irqreturn_t timer_interrupt(int irq, void *dev_id)
if (timer_ack) {
/*
* Subtle, when I/O APICs are used we have to ack timer IRQ
- * manually to reset the IRR bit for do_slow_gettimeoffset().
- * This will also deassert NMI lines for the watchdog if run
+ * manually to deassert NMI lines for the watchdog if run
* on an 82489DX-based system.
*/
spin_lock(&i8259A_lock);