From mboxrd@z Thu Jan 1 00:00:00 1970 From: daniel.lezcano@linaro.org (Daniel Lezcano) Date: Mon, 04 May 2015 10:44:18 +0200 Subject: [PATCH 1/7] clocksource: mediatek: Don't run event_handler if it is NULL In-Reply-To: References: <1430466210-22963-1-git-send-email-yingjoe.chen@mediatek.com> <1430466210-22963-2-git-send-email-yingjoe.chen@mediatek.com> <55472A80.9020904@linaro.org> Message-ID: <55473162.5010608@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 05/04/2015 10:34 AM, Matthias Brugger wrote: > 2015-05-04 10:14 GMT+02:00 Daniel Lezcano : >> 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 >>> --- >>> 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 ? -- Linaro.org ? Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog