Hi,
On 03/06/2015 03:54 AM, Mark Rutland wrote:
> Hi,
>
>>>>>> + psci {
>>>>>> + compatible = "arm,psci";
>>>>>> + method = "smc";
>>>>>> + cpu_off = <0x84000002>;
>>>>>> + cpu_on = <0xC4000003>;
>>>>>> + };
>>>>>
>>>>> Back at v2 you mentioned that CPU_OFF wasn't working [1].
>>>>>
>>>>> Do both CPU_ON and CPU_OFF work for all CPUs, including the boot CPU?
>>>>
>>>> The CPU1 ~ CPU7 are well woking about CPU_ON/OFF.
>>>> CPU0 (boot CPU) is only well working for CPU_OFF.
>>>> But when I try to turn on the CPU0 after CPU_OFF, I failed it.
>>>
>>> That's rather worrying. Can you look into what's going on here? I'd
>>> rather not have dts describing things which are known to be broken.
>>
>> The board dts don't include any node for CPU_ON/OFF.
>
> I don't understand. The CPU_ON and CPU_OFF IDs are in the psci node
> quoted above, and all the CPUs had enable-method = "psci".
I mean that there are not additional dt node except for 'cpu' and 'psci' node.
>
>> When I try to turn on the CPU0 (boot CPU), fail to turn on and lockup happen.
>> After lockup happen, I cannot use the console.
>
> That sounds like a pretty major bug.
>
> Are you able to investigate with a hardware debugger?
I can't do because there are not any jtag connector.
>
> Do other CPUs eventually log errors regarding the lockup? Or is the
> machine completely dead from this point on?
I tested CPU0 on/off. When I turn on the CPU0, I fail it. But, kernel just show
the error log without lockup.
I gave you wrong infromation about CPU0 off.
[test result of CPU0 on/off on Linux 4.0-rc2]
root@localhost:~# echo 0 > /sys/devices/system/cpu/cpu0/online
[ 420.965435] IRQ1 no longer affine to CPU0
[ 420.965439] IRQ2 no longer affine to CPU0
[ 4631.194227] CPU0: shutdown
root@localhost:~# echo 1 > /sys/devices/system/cpu/cpu0/online
[ 1164.601644] CPU0: failed to come online
-bash: echo: write error: Input/output error
As I experienced, Exynos SoC could not turn off the CPU0 (boot cpu).
I think that we may need the hidden information of Exynos5433 from Exynos5433
architector.
>
>>>>> I take it CPUs boot at EL2?
>>>
>>> Do the CPUs boot at EL1 or EL2?
>>
>> Unfortunately, I cannot check the secure firmware for Exynos5433 SoC.
>> I think that a few SoC provider probably would know it.
>
> I guess I asked the wrong question.
>
> Do CPUs enter the kernel at EL2 or at EL1?
Could you give me a tip how to check the kernel at EL2 or EL1?
Thanks,
Chanwoo Choi
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