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 <dayu@datangmobile.cn>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
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 @@
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 @@
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