From: Wang Dongsheng <dongsheng.w...@freescale.com>
Currently MPIC provides .mask, but not .disable. This means that
effectively disable_irq() soft-disables the interrupt, and you get
a .mask call if an interrupt actually occurs.
I'm not sure if this was intended as a performance benefit (it seems common
to omit .disable on powerpc interrupt controllers, but nowhere else), but it
interacts badly with threaded/workqueue interrupts (including KVM
reflection). In such cases, where the real interrupt handler does a
disable_irq_nosync(), schedules defered handling, and returns, we get two
interrupts for every real interrupt. The second interrupt does nothing
but see that IRQ_DISABLED is set, and decide that it would be a good
idea to actually call .mask.
Signed-off-by: Scott Wood <scottw...@freescale.com>
Signed-off-by: Wang Dongsheng <dongsheng.w...@freescale.com>
diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
index 0e166ed..dd7564b 100644
--- a/arch/powerpc/sysdev/mpic.c
+++ b/arch/powerpc/sysdev/mpic.c
@@ -975,6 +975,7 @@ void mpic_set_destination(unsigned int virq, unsigned int
cpuid)
}
static struct irq_chip mpic_irq_chip = {
+ .irq_disable = mpic_mask_irq,
.irq_mask = mpic_mask_irq,
.irq_unmask = mpic_unmask_irq,
.irq_eoi = mpic_end_irq,
@@ -984,6 +985,7 @@ static struct irq_chip mpic_irq_chip = {
#ifdef CONFIG_SMP
static struct irq_chip mpic_ipi_chip = {
+ .irq_disable = mpic_mask_ipi,
.irq_mask = mpic_mask_ipi,
.irq_unmask = mpic_unmask_ipi,
.irq_eoi = mpic_end_ipi,
@@ -991,6 +993,7 @@ static struct irq_chip mpic_ipi_chip = {
#endif /* CONFIG_SMP */
static struct irq_chip mpic_tm_chip = {
+ .irq_disable = mpic_mask_tm,
.irq_mask = mpic_mask_tm,
.irq_unmask = mpic_unmask_tm,
.irq_eoi = mpic_end_irq,
@@ -1001,6 +1004,7 @@ static struct irq_chip mpic_tm_chip = {
static struct irq_chip mpic_irq_ht_chip = {
.irq_startup = mpic_startup_ht_irq,
.irq_shutdown = mpic_shutdown_ht_irq,
+ .irq_disable = mpic_mask_irq,
.irq_mask = mpic_mask_irq,
.irq_unmask = mpic_unmask_ht_irq,
.irq_eoi = mpic_end_ht_irq,
--
1.8.5
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