---

yaml --- r: 99316 b: refs/heads/master c: d11d579 h: refs/heads/master v: v3
git-mirror · Jul 8, 2008 · 33c741c · 33c741c
1 parent cc9fff9
commit 33c741c
Show file tree

Hide file tree

Showing 5 changed files with 14 additions and 20 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: a0176e2485ce6468f9b74264a2fd6c19811f027a
+refs/heads/master: d11d5794e0c21a1054e6cd57381050a999ad7232
diff --git a/trunk/arch/x86/kernel/io_apic_32.c b/trunk/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/trunk/arch/x86/kernel/io_apic_64.c b/trunk/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/trunk/arch/x86/kernel/nmi_32.c b/trunk/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/trunk/arch/x86/kernel/time_32.c b/trunk/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);