MCA_bus is constant 0 when CONFIG_MCA=n. So the compiler removes that code w/o needing an extra #ifdef Signed-off-by: Thomas Gleixner --- arch/x86/kernel/time_32.c | 18 +++--------------- arch/x86/kernel/time_64.c | 9 +++------ 2 files changed, 6 insertions(+), 21 deletions(-) Index: linux-2.6/arch/x86/kernel/time_32.c =================================================================== --- linux-2.6.orig/arch/x86/kernel/time_32.c +++ linux-2.6/arch/x86/kernel/time_32.c @@ -77,21 +77,9 @@ static irqreturn_t timer_interrupt(int i global_clock_event->event_handler(global_clock_event); -#ifdef CONFIG_MCA - if (MCA_bus) { - /* The PS/2 uses level-triggered interrupts. You can't - turn them off, nor would you want to (any attempt to - enable edge-triggered interrupts usually gets intercepted by a - special hardware circuit). Hence we have to acknowledge - the timer interrupt. Through some incredibly stupid - design idea, the reset for IRQ 0 is done by setting the - high bit of the PPI port B (0x61). Note that some PS/2s, - notably the 55SX, work fine if this is removed. */ - - u8 irq_v = inb_p(0x61); /* read the current state */ - outb_p(irq_v | 0x80, 0x61); /* reset the IRQ */ - } -#endif + /* MCA bus quirk: Acknowledge irq0 by setting bit 7 in port 0x61 */ + if (MCA_bus) + outb_p(inb_p(0x61)| 0x80, 0x61); return IRQ_HANDLED; } Index: linux-2.6/arch/x86/kernel/time_64.c =================================================================== --- linux-2.6.orig/arch/x86/kernel/time_64.c +++ linux-2.6/arch/x86/kernel/time_64.c @@ -66,12 +66,9 @@ static irqreturn_t timer_interrupt(int i global_clock_event->event_handler(global_clock_event); -#ifdef CONFIG_MCA - if (MCA_bus) { - u8 irq_v = inb_p(0x61); /* read the current state */ - outb_p(irq_v|0x80, 0x61); /* reset the IRQ */ - } -#endif + /* MCA bus quirk: Acknowledge irq0 by setting bit 7 in port 0x61 */ + if (MCA_bus) + outb_p(inb_p(0x61)| 0x80, 0x61); return IRQ_HANDLED; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/