Re: [PATCH] ARM: EXYNOS4: Fix soft reboot hang after suspend/resume

[Inderpal Singh <inderpal.singh@xxxxxxxxxx>]

Hi Kukjin,

On 14 May 2012 19:13, Kukjin Kim <kgene.kim@xxxxxxxxxxx> wrote:
> On 05/14/12 17:42, Inderpal Singh wrote:
>>
>> Hi Kukjin,
>>
>> On 14 May 2012 13:45, Kukjin Kim<kgene.kim@xxxxxxxxxxx>  wrote:
>>>
>>> Inderpal Singh wrote:
>>>>
>>>>
>>>> Upon wake-up, clear the sleep mode set in INFORM1 register.
>>>>
>>> Is this for wake-up or _really_ software reset? And is this available on
>>> all
>>> of EXYNOS4 SoCs?
>>
>>
>> This is for soft reboot hang after one cycle of suspend/resume is
>> complete.
>> And yes this is applicable for all exynos SOCs.
>>
> Hi,
>
> As I know, we don't need it for all of EXYNOS SoCs but let me check about
> the situation you said with hardware engineer tomorrow. If any updates, let
> you know.
>

The issue happens because u-boot checks INFROM1 register to know if
its wake-up from sleep. Hence if INFORM1 is not cleared, the soft
reboot after one suspend/resume cycle will be understood by u-boot as
wake-up from sleep, so it will try to resume and will hang up.

I have faced this issue on Origen, Pegasus SMDK and 5250 SMDK.

Thanks,
Inder

>
> Thanks.
>
> Best regards,
> Kgene.
> --
> Kukjin Kim <kgene.kim@xxxxxxxxxxx>, Senior Engineer,
> SW Solution Development Team, Samsung Electronics Co., Ltd.
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