[RFC patch 25/32] x86: Remove mca bus ifdef from timer interrupt

Thomas Gleixner
2009-08-21T21:35:21Z

[-- Attachment #1: x86-time-remove-mca-bus-ifdef.patch --]
[-- Type: text/plain, Size: 2034 bytes --]

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 <tglx@linutronix.de>
---
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;
}