| From 5b28df58db43f29fc7d87d005243a2c1c6280425 Mon Sep 17 00:00:00 2001 |
| From: Ingo Molnar <mingo@elte.hu> |
| Date: Fri, 3 Jul 2009 08:29:35 -0500 |
| Subject: [PATCH] x86: Optimize and fix the 8259 ack code for -rt |
| |
| commit 600b1f32140d45f06ddbe68db9788f6f59013e8b in tip. |
| |
| Signed-off-by: Ingo Molnar <mingo@elte.hu> |
| Signed-off-by: Thomas Gleixner <tglx@linutronix.de> |
| |
| diff --git a/arch/x86/kernel/i8259.c b/arch/x86/kernel/i8259.c |
| index 8c93a84..96400fe 100644 |
| --- a/arch/x86/kernel/i8259.c |
| +++ b/arch/x86/kernel/i8259.c |
| @@ -168,6 +168,8 @@ static void mask_and_ack_8259A(unsigned int irq) |
| */ |
| if (cached_irq_mask & irqmask) |
| goto spurious_8259A_irq; |
| + if (irq & 8) |
| + outb(0x60+(irq&7), PIC_SLAVE_CMD); /* 'Specific EOI' to slave */ |
| cached_irq_mask |= irqmask; |
| |
| handle_real_irq: |
| @@ -328,10 +330,10 @@ void init_8259A(int auto_eoi) |
| /* 8259A-1 (the master) has a slave on IR2 */ |
| outb_pic(1U << PIC_CASCADE_IR, PIC_MASTER_IMR); |
| |
| - if (auto_eoi) /* master does Auto EOI */ |
| - outb_pic(MASTER_ICW4_DEFAULT | PIC_ICW4_AEOI, PIC_MASTER_IMR); |
| - else /* master expects normal EOI */ |
| - outb_pic(MASTER_ICW4_DEFAULT, PIC_MASTER_IMR); |
| + if (!auto_eoi) /* master expects normal EOI */ |
| + outb_p(MASTER_ICW4_DEFAULT, PIC_MASTER_IMR); |
| + else /* master does Auto EOI */ |
| + outb_p(MASTER_ICW4_DEFAULT | PIC_ICW4_AEOI, PIC_MASTER_IMR); |
| |
| outb_pic(0x11, PIC_SLAVE_CMD); /* ICW1: select 8259A-2 init */ |
| |
| -- |
| 1.7.1.1 |
| |
