On Mon, 2015-05-04 at 10:44 +0200, Daniel Lezcano wrote: > On 05/04/2015 10:34 AM, Matthias Brugger wrote: > > 2015-05-04 10:14 GMT+02:00 Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>: > >> On 05/01/2015 09:43 AM, Yingjoe Chen wrote: > >>> > >>> Spurious timer interrupt is noticed in mtk timer and cause kernel > >>> crash. In mtk_timer_interrupt(), only run event_handler if it is > >>> not NULL. > >>> > >>> Signed-off-by: Yingjoe Chen <yingjoe.chen@xxxxxxxxxxxx> > >>> --- > >>> drivers/clocksource/mtk_timer.c | 3 ++- > >>> 1 file changed, 2 insertions(+), 1 deletion(-) > >>> > >>> diff --git a/drivers/clocksource/mtk_timer.c > >>> b/drivers/clocksource/mtk_timer.c > >>> index 68ab423..85e0ab5 100644 > >>> --- a/drivers/clocksource/mtk_timer.c > >>> +++ b/drivers/clocksource/mtk_timer.c > >>> @@ -143,7 +143,8 @@ static irqreturn_t mtk_timer_interrupt(int irq, void > >>> *dev_id) > >>> > >>> /* Acknowledge timer0 irq */ > >>> writel(GPT_IRQ_ACK(GPT_CLK_EVT), evt->gpt_base + GPT_IRQ_ACK_REG); > >>> - evt->dev.event_handler(&evt->dev); > >>> + if (evt->dev.event_handler) > >>> + evt->dev.event_handler(&evt->dev); > >>> > >>> return IRQ_HANDLED; > >>> } > >>> > >> > >> This fix does not look good. > >> > >> Could you try by requesting the irq *after* clockevents_config_and_register > >> in the init sequence [1] ? > >> > > > > From my understanding [1] should already fix this. > > > > [1] https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/commit/drivers/clocksource/mtk_timer.c?id=d4a19eb3b15a4ba98f627182f48d5bc0cffae670 > > Indeed it seems to fix it. But I think request_irq should be done after > clockevents_config_and_register in any case. > > Yingjoe, are the spurious interrupts occurring with the fix Matthias > mentions ? > Hi Daniel, Matthias, Thanks for your review. Unfortunately, I still saw the spurious interrupts with both fixes. After some experiments, it seems the HW will latch irq status even when IRQ is disabled. I can fix this issue by either ack irq before enable irq(like patch below), or not enable clock event before enable irq. I'll come up a fix base on this next time. diff --git a/drivers/clocksource/mtk_timer.c b/drivers/clocksource/mtk_timer.c index 9a90c7b..c5f804a 100644 --- a/drivers/clocksource/mtk_timer.c +++ b/drivers/clocksource/mtk_timer.c @@ -184,6 +183,7 @@ static void mtk_timer_enable_irq(struct mtk_clock_event_device *evt, u8 timer) { u32 val; + writel(GPT_IRQ_ENABLE(timer), evt->gpt_base + GPT_IRQ_ACK_REG); val = readl(evt->gpt_base + GPT_IRQ_EN_REG); writel(val | GPT_IRQ_ENABLE(timer), evt->gpt_base + GPT_IRQ_EN_REG); Joe.C -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
