x86: I/O APIC: timer through 8259A second-chance

[linux-2.6-omap-h63xx.git] / arch / x86 / kernel / io_apic_32.c

diff --git a/arch/x86/kernel/io_apic_32.c b/arch/x86/kernel/io_apic_32.c
index 63a2f64c765b6c4d37b6ee1778e1eac1416f6d02..a69a59d19e187999184a398fa28af9828167c20f 100644 (file)
--- a/arch/x86/kernel/io_apic_32.c
+++ b/arch/x86/kernel/io_apic_32.c
@@ -2122,6 +2122,7 @@ static inline void __init unlock_ExtINT_logic(void)
 static inline void __init check_timer(void)
 {
        int apic1, pin1, apic2, pin2;
+       int no_pin1 = 0;
        int vector;
        unsigned int ver;
        unsigned long flags;
@@ -2159,10 +2160,30 @@ static inline void __init check_timer(void)
        printk(KERN_INFO "..TIMER: vector=0x%02X apic1=%d pin1=%d apic2=%d pin2=%d\n",
                vector, apic1, pin1, apic2, pin2);
 
+       /*
+        * Some BIOS writers are clueless and report the ExtINTA
+        * I/O APIC input from the cascaded 8259A as the timer
+        * interrupt input.  So just in case, if only one pin
+        * was found above, try it both directly and through the
+        * 8259A.
+        */
+       if (pin1 == -1) {
+               pin1 = pin2;
+               apic1 = apic2;
+               no_pin1 = 1;
+       } else if (pin2 == -1) {
+               pin2 = pin1;
+               apic2 = apic1;
+       }
+
        if (pin1 != -1) {
                /*
                 * Ok, does IRQ0 through the IOAPIC work?
                 */
+               if (no_pin1) {
+                       add_pin_to_irq(0, apic1, pin1);
+                       setup_timer_IRQ0_pin(apic1, pin1, vector);
+               }
                unmask_IO_APIC_irq(0);
                if (timer_irq_works()) {
                        if (nmi_watchdog == NMI_IO_APIC) {
@@ -2174,26 +2195,23 @@ static inline void __init check_timer(void)
                        goto out;
                }
                clear_IO_APIC_pin(apic1, pin1);
-               printk(KERN_ERR "..MP-BIOS bug: 8254 timer not connected to "
-                               "IO-APIC\n");
-       }
+               if (!no_pin1)
+                       printk(KERN_ERR "..MP-BIOS bug: "
+                              "8254 timer not connected to IO-APIC\n");
 
-       printk(KERN_INFO "...trying to set up timer (IRQ0) through the 8259A ... ");
-       if (pin2 != -1) {
+               printk(KERN_INFO "...trying to set up timer (IRQ0) "
+                      "through the 8259A ... ");
                printk("\n..... (found pin %d) ...", pin2);
                /*
                 * legacy devices should be connected to IO APIC #0
                 */
+               replace_pin_at_irq(0, apic1, pin1, apic2, pin2);
                setup_timer_IRQ0_pin(apic2, pin2, vector);
                unmask_IO_APIC_irq(0);
                enable_8259A_irq(0);
                if (timer_irq_works()) {
                        printk("works.\n");
                        timer_through_8259 = 1;
-                       if (pin1 != -1)
-                               replace_pin_at_irq(0, apic1, pin1, apic2, pin2);
-                       else
-                               add_pin_to_irq(0, apic2, pin2);
                        if (nmi_watchdog == NMI_IO_APIC) {
                                disable_8259A_irq(0);
                                setup_nmi();
@@ -2206,8 +2224,8 @@ static inline void __init check_timer(void)
                 */
                disable_8259A_irq(0);
                clear_IO_APIC_pin(apic2, pin2);
+               printk(" failed.\n");
        }
-       printk(" failed.\n");
 
        if (nmi_watchdog == NMI_IO_APIC) {
                printk(KERN_WARNING "timer doesn't work through the IO-APIC - disabling NMI Watchdog!\n");