diff options
| -rw-r--r-- | arch/arm/mach-dove/irq.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/arch/arm/mach-dove/irq.c b/arch/arm/mach-dove/irq.c index 087711524e8a..bc4344aa1009 100644 --- a/arch/arm/mach-dove/irq.c +++ b/arch/arm/mach-dove/irq.c @@ -46,8 +46,20 @@ static void pmu_irq_ack(struct irq_data *d) int pin = irq_to_pmu(d->irq); u32 u; + /* + * The PMU mask register is not RW0C: it is RW. This means that + * the bits take whatever value is written to them; if you write + * a '1', you will set the interrupt. + * + * Unfortunately this means there is NO race free way to clear + * these interrupts. + * + * So, let's structure the code so that the window is as small as + * possible. + */ u = ~(1 << (pin & 31)); - writel(u, PMU_INTERRUPT_CAUSE); + u &= readl_relaxed(PMU_INTERRUPT_CAUSE); + writel_relaxed(u, PMU_INTERRUPT_CAUSE); } static struct irq_chip pmu_irq_chip = { |