Re: Suspend-resume failure on Intel Eagle Lake Core2Duo

[Marc Zyngier]

On 03/08/17 13:52, Masahiro Yamada wrote:
> Hi Marc,
> 
> 2017-08-03 17:41 GMT+09:00 Marc Zyngier <marc.zyngier@xxxxxxx>:
>> Hi Masahiro,
>>
>> On 03/08/17 08:32, Masahiro Yamada wrote:
>>> Hi.
>>>
>>> 2017-08-01 0:55 GMT+09:00 Thomas Gleixner <tglx@xxxxxxxxxxxxx>:
>>>> On Mon, 31 Jul 2017, Tomi Sarvela wrote:
>>>>> On 31/07/17 18:06, Thomas Gleixner wrote:
>>>>>> Can you please remove the patch. And try the following:
>>>>>>
>>>>>> # echo N > /sys/module/printk/parameters/console_suspend
>>>>>>
>>>>>> # echo mem > /sys/power/state
>>>>>>
>>>>>> and log the output of the serial console. That way we might get a clue
>>>>>> where it gets stuck.
>>>>>
>>>>> I'm afraid it hangs right away. No response from SSH, no output to serial.
>>>>
>>>> What means hangs right away? Is there no output at all on the serial
>>>> console? Or does it just stop at some point?
>>>>
>>>> Thanks,
>>>>
>>>>         tglx
>>>>
>>>
>>> Sorry for jumping in.
>>> Finally, I found this thread.
>>>
>>>
>>> My environment is completely different (ARM64 board),
>>> I am also suffering from a hibernation problem
>>> since this commit.
>>>
>>>
>>> I get no response on the serial console
>>> after "Restarting tasks ... done." log message.
>>>
>>>
>>> By reverting bf22ff45bed6 ("genirq: Avoid unnecessary low level
>>> irq function calls", I can get hibernation working again.
>>>
>>>
>>> SW info:
>>> defconfig:  arch/arm64/configs/defconfig
>>> DT       :  arch/arm64/boot/dts/socionext/uniphier-ld20-ref.dts
>>> PSCI     :  ARM Trusted Firmware
>>>
>>>
>>> SoC info:
>>> CPU      :  Cortex-A72 * 2 + Cortex-A53 * 2
>>> irqchip  :  GICv3 (drivers/irq/irq-gic-v3.c)
>>
>> Let me take an educated guess: It feels like your firmware doesn't
>> save/restore the GIC context across suspend/resume. Is that something
>> you could check, assuming you have access to the firmware source code?
> 
> Thanks for your comments.
> 
> 
> I do not know much about the manner of preserving GICv3 context.
> 
> I can see this patch  (rejected?) :
> https://patchwork.kernel.org/patch/9343061/
> 
> 
> Is it something that should be completely cared by firmware
> instead of kernel?

That was definitely the intention, but it looks like something that ATF
has only started supporting very recently:

https://github.com/ARM-software/arm-trusted-firmware/pull/1047

> ARM Trusted Firmware (https://github.com/ARM-software/arm-trusted-firmware)
> is open source software, and I pushed my platform code to the upstream.
> 
> So, yes, I (and everybody) can have access to the firmware source code.
> 
> 
> I am not sure how ATF saves the context during hibernation, though.

See the above link. Is there any chance of you trying this into your
firmware?

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...