[PATCH 2/5] clocksource: rockchip: remove unnecessary clear irq before request_irq

Daniel Lezcano daniel.lezcano at linaro.org
Mon May 30 16:09:45 PDT 2016


On 05/25/2016 11:49 AM, Caesar Wang wrote:
> From: Huang Tao <huangtao at rock-chips.com>
>
> rk_timer_interrupt_clear and rk_timer_disable is unnecessary before
> request_irq. Timer should keep disabled before booting Linux.

That's true in the perfect world :/ Some version has u-boot letting the 
timer with irq enabled, therefore as soon as request_irq is done, an irq 
fires and leads to a kernel panic.

On the other side, this timer is not used on the other rockchip version 
than rk3399 because of no need of a broadcast timer, so removing these 
two lines may be acceptable.

Can try the changes with another board, eg rk3288 (and forcing to use 
this timer). Can you do the test and confirm it does not break with 
different version of u-boot ?

Thanks!

   -- Daniel

> Signed-off-by: Huang Tao <huangtao at rock-chips.com>
> Cc: Daniel Lezcano <daniel.lezcano at linaro.org>
> Cc: Thomas Gleixner <tglx at linutronix.de>
> Cc: Heiko Stuebner <heiko at sntech.de>
> Tested-by: Jianqun Xu <jay.xu at rock-chips.com>
> Signed-off-by: Caesar Wang <wxt at rock-chips.com>
> ---
>
>   drivers/clocksource/rockchip_timer.c | 3 ---
>   1 file changed, 3 deletions(-)
>
> diff --git a/drivers/clocksource/rockchip_timer.c b/drivers/clocksource/rockchip_timer.c
> index b991b28..b93fed6 100644
> --- a/drivers/clocksource/rockchip_timer.c
> +++ b/drivers/clocksource/rockchip_timer.c
> @@ -158,9 +158,6 @@ static void __init rk_timer_init(struct device_node *np)
>   	ce->cpumask = cpumask_of(0);
>   	ce->rating = 250;
>
> -	rk_timer_interrupt_clear(ce);
> -	rk_timer_disable(ce);
> -
>   	ret = request_irq(irq, rk_timer_interrupt, IRQF_TIMER, TIMER_NAME, ce);
>   	if (ret) {
>   		pr_err("Failed to initialize '%s': %d\n", TIMER_NAME, ret);
>


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