From 30c404699dd650f213d480d263c775915a0e1297 Mon Sep 17 00:00:00 2001 From: "dayu@datangmobile.cn" Date: Wed, 18 Feb 2009 13:47:42 +0800 Subject: [PATCH] powerpc/83xx: Fix the interrupt loss problem on ipic The interrupt pending register is write 1 clear. If there are more than one external interrupts pending at the same time, acking the first interrupt by reading pending register then OR the corresponding bit and write back to pending register will also clear other interrupt pending bits. That will cause loss of interrupt. Signed-off-by: Da Yu Signed-off-by: Kumar Gala --- arch/powerpc/sysdev/ipic.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/sysdev/ipic.c b/arch/powerpc/sysdev/ipic.c index 9a89cd3..a86d3ce 100644 --- a/arch/powerpc/sysdev/ipic.c +++ b/arch/powerpc/sysdev/ipic.c @@ -568,8 +568,7 @@ static void ipic_ack_irq(unsigned int virq) spin_lock_irqsave(&ipic_lock, flags); - temp = ipic_read(ipic->regs, ipic_info[src].ack); - temp |= (1 << (31 - ipic_info[src].bit)); + temp = 1 << (31 - ipic_info[src].bit); ipic_write(ipic->regs, ipic_info[src].ack, temp); /* mb() can't guarantee that ack is finished. But it does finish @@ -592,8 +591,7 @@ static void ipic_mask_irq_and_ack(unsigned int virq) temp &= ~(1 << (31 - ipic_info[src].bit)); ipic_write(ipic->regs, ipic_info[src].mask, temp); - temp = ipic_read(ipic->regs, ipic_info[src].ack); - temp |= (1 << (31 - ipic_info[src].bit)); + temp = 1 << (31 - ipic_info[src].bit); ipic_write(ipic->regs, ipic_info[src].ack, temp); /* mb() can't guarantee that ack is finished. But it does finish -- 2.7.4