From 691874fa96d6349a8b60f8ea9c2bae52ece79941 Mon Sep 17 00:00:00 2001 From: "Maciej W. Rozycki" Date: Tue, 27 May 2008 21:19:51 +0100 Subject: [PATCH] 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 Signed-off-by: Ingo Molnar --- arch/x86/kernel/io_apic_32.c | 38 ++++++++++++++++++++++++++---------- arch/x86/kernel/io_apic_64.c | 36 +++++++++++++++++++++++++++------- 2 files changed, 57 insertions(+), 17 deletions(-) diff --git a/arch/x86/kernel/io_apic_32.c b/arch/x86/kernel/io_apic_32.c index 63a2f64c76..a69a59d19e 100644 --- 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"); diff --git a/arch/x86/kernel/io_apic_64.c b/arch/x86/kernel/io_apic_64.c index ae0ac99057..9a54b779ab 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"); -- 2.39.5