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authorMaciej W. Rozycki <macro@linux-mips.org>2008-05-27 21:19:51 +0100
committerIngo Molnar <mingo@elte.hu>2008-07-08 09:13:07 +0200
commit691874fa96d6349a8b60f8ea9c2bae52ece79941 (patch)
treea705c041eb25329632eab0491244b4544218273b /arch/x86/kernel/io_apic_64.c
parent03be750559b2fe20d85dd968e08d5fe1c3accf83 (diff)
x86: I/O APIC: timer through 8259A second-chance
Some systems incorrectly report the ExtINTA pin of the I/O APIC as the genuine target of the timer interrupt. Here is a change that copies timer pin information found to the other pin if one has been found only. This way both a direct and a through-8259A route is tested with the pin letting these problematic systems work well enough. If no timer pin information has been found for the I/O APIC, then local APIC variations are tried only, similarly to what is done without the change (except without the misleading messages). Obviously if we try the first-chance path without being told by the BIOS to do so, we should not complain either, so do not print the message in this case. The 64-bit variation should be updated with a call to replace_pin_at_irq() which can be done with the upcoming merge. Since add_pin_to_irq() is now always called in the first-chance path, the condition to require it in the second-chance path no longer happens. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/io_apic_64.c')
-rw-r--r--arch/x86/kernel/io_apic_64.c36
1 files changed, 29 insertions, 7 deletions
diff --git a/arch/x86/kernel/io_apic_64.c b/arch/x86/kernel/io_apic_64.c
index ae0ac990574..9a54b779abd 100644
--- a/arch/x86/kernel/io_apic_64.c
+++ b/arch/x86/kernel/io_apic_64.c
@@ -1638,6 +1638,7 @@ static inline void __init check_timer(void)
struct irq_cfg *cfg = irq_cfg + 0;
int apic1, pin1, apic2, pin2;
unsigned long flags;
+ int no_pin1 = 0;
local_irq_save(flags);
@@ -1662,10 +1663,30 @@ static inline void __init check_timer(void)
apic_printk(APIC_VERBOSE,KERN_INFO "..TIMER: vector=0x%02X apic1=%d pin1=%d apic2=%d pin2=%d\n",
cfg->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 (!no_timer_check && timer_irq_works()) {
nmi_watchdog_default();
@@ -1678,18 +1699,19 @@ static inline void __init check_timer(void)
goto out;
}
clear_IO_APIC_pin(apic1, pin1);
- apic_printk(APIC_QUIET,KERN_ERR "..MP-BIOS bug: 8254 timer not "
- "connected to IO-APIC\n");
- }
+ if (!no_pin1)
+ apic_printk(APIC_QUIET,KERN_ERR "..MP-BIOS bug: "
+ "8254 timer not connected to IO-APIC\n");
- apic_printk(APIC_VERBOSE,KERN_INFO "...trying to set up timer (IRQ0) "
- "through the 8259A ... ");
- if (pin2 != -1) {
+ apic_printk(APIC_VERBOSE,KERN_INFO
+ "...trying to set up timer (IRQ0) "
+ "through the 8259A ... ");
apic_printk(APIC_VERBOSE,"\n..... (found apic %d pin %d) ...",
apic2, 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, cfg->vector);
unmask_IO_APIC_irq(0);
enable_8259A_irq(0);
@@ -1709,8 +1731,8 @@ static inline void __init check_timer(void)
*/
disable_8259A_irq(0);
clear_IO_APIC_pin(apic2, pin2);
+ apic_printk(APIC_VERBOSE," failed.\n");
}
- apic_printk(APIC_VERBOSE," failed.\n");
if (nmi_watchdog == NMI_IO_APIC) {
printk(KERN_WARNING "timer doesn't work through the IO-APIC - disabling NMI Watchdog!\n");