From mboxrd@z Thu Jan 1 00:00:00 1970 From: daniel.lezcano@linaro.org (Daniel Lezcano) Date: Mon, 24 Aug 2015 15:30:44 +0200 Subject: [PATCH] clockevents/drivers/mtk: Fix spurious interrupt leading to crash In-Reply-To: <1440167950.20169.29.camel@mtksdaap41> References: <1440167950.20169.29.camel@mtksdaap41> Message-ID: <1440423045-7883-1-git-send-email-daniel.lezcano@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org After analysis done by Yingjoe Chen, the timer appears to have a pending interrupt when it is enabled. Fix this by acknowledging the pending interrupt when enabling the timer interrupt. Signed-off-by: Daniel Lezcano --- drivers/clocksource/mtk_timer.c | 13 +++---------- 1 file changed, 3 insertions(+), 10 deletions(-) diff --git a/drivers/clocksource/mtk_timer.c b/drivers/clocksource/mtk_timer.c index 4cd16fb..13543a8 100644 --- a/drivers/clocksource/mtk_timer.c +++ b/drivers/clocksource/mtk_timer.c @@ -156,14 +156,6 @@ static irqreturn_t mtk_timer_interrupt(int irq, void *dev_id) return IRQ_HANDLED; } -static void mtk_timer_global_reset(struct mtk_clock_event_device *evt) -{ - /* Disable all interrupts */ - writel(0x0, evt->gpt_base + GPT_IRQ_EN_REG); - /* Acknowledge all interrupts */ - writel(0x3f, evt->gpt_base + GPT_IRQ_ACK_REG); -} - static void mtk_timer_setup(struct mtk_clock_event_device *evt, u8 timer, u8 option) { @@ -183,6 +175,9 @@ static void mtk_timer_enable_irq(struct mtk_clock_event_device *evt, u8 timer) { u32 val; + /* Acknowledge all spurious pending interrupts */ + writel(0x3f, 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); @@ -232,8 +227,6 @@ static void __init mtk_timer_init(struct device_node *node) } rate = clk_get_rate(clk); - mtk_timer_global_reset(evt); - if (request_irq(evt->dev.irq, mtk_timer_interrupt, IRQF_TIMER | IRQF_IRQPOLL, "mtk_timer", evt)) { pr_warn("failed to setup irq %d\n", evt->dev.irq); -- 1.9.1