On 05/22/2013 11:47 AM, Lu Jingchang-B35083 wrote:
>
[ ... ]
>>
>>> +}
>>> +
>>> +static void __init pit_timer_init(struct device_node *np) {
>>> + struct clk *pit_clk;
>>> + void __iomem *timer_base;
>>> + int irq;
>>> +
>>> + timer_base = of_iomap(np, 0);
>>> + BUG_ON(!timer_base);
>>
>> You raise a bug and then you go ahead setting up the address with an
>> invalid value, leading to a random crash.
> [Lu Jingchang-B35083]
> The BUG_ON() will call BUG() if condition is true. It will print the stack
> trace and the current process will die, it won't go ahead, won't it? Thanks!
Pff, right. I just puzzled myself. Never mind.
>>> + /*
>>> + * PIT0 and PIT1 can be chained to build a 64-bit timer,
>>> + * so choose PIT2 as clocksource, PIT3 as clockevent device,
>>> + * and leave PIT0 and PIT1 unused for anyone else who needs them.
>>> + */
>>> + clksrc_base = timer_base + PITn_OFFSET(2);
>>> + clkevt_base = timer_base + PITn_OFFSET(3);
>>> +
>>> + irq = irq_of_parse_and_map(np, 0);
>>> +
>>> + pit_clk = of_clk_get(np, 0);
>>> + BUG_ON(IS_ERR(pit_clk));
>>> +
>>> + BUG_ON(clk_prepare_enable(pit_clk));
>>
>> Same here.
>>
>>> + cycle_per_jiffy = clk_get_rate(pit_clk)/(HZ);
>>> +
>>> + /* enable the pit module */
>>> + __raw_writel(~PITMCR_MDIS, timer_base + PITMCR);
>>> +
>>> + BUG_ON(pit_clocksource_init(pit_clk));
>>> +
>>> + pit_clockevent_init(pit_clk, irq);
>>
>> Please, remove these BUG_ON, this is inconsistent especially with a one
>> call init function. If pit_timer_init can't be initialized, just pr_err
>> + BUG.
> [Lu Jingchang-B35083]
> Do you mean that I should not use the BUG_ON or I need print an error
> information by pr_err before BUG. Thanks!
Actually, my initial comment was wrong, so you can ignore it.
Thank
-- Daniel
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